Prevalence of Segond fractures associated with anterior cruciate ligament injuries and their influence on knee joint stability; A case-control study.

BACKGROUND: The purpose of this study was to determine the prevalence of Segond fractures and to compare knee stability between patients undergoing primary anterior cruciate ligament (ACL) reconstruction with and without Segond fractures pre- and postoperatively. METHODS: A total of 712 patients who underwent primary ACL reconstruction between 2014 and 2019. Exclusion criteria included patients with multi-ligament knee injuries, skeletally immature patients, osteoarthritis in the knee, combined surgery of high tibial osteotomy, lack of data, and loss to follow-up for at least 2 years. Segond fractures were confirmed using plain radiography, computed tomography (CT), and magnetic resonance imaging (MRI). Patients with Segond fractures were classified into Group S and without Segond fractures into Group N. Pre- and postoperative Lachman grades, pivot-shift grades, and assessment of side-to-side differences in anterior stability were evaluated. RESULTS: Five hundred and forty patients included in this study. There were 22 patients with Segond fractures. Of these, all 22 cases (4.1%) were identified on CT, but only 20 cases (3.7%) were identified on MRI and 18 cases (3.3%) on plain radiographs. There was no significant difference in preoperative Lachman grade or pivot-shift grade between Groups S and N (p = 0.662, p = 0.677, respectively). There was no significant difference in postoperative Lachman grade or pivot-shift grade between Groups S and N (p = 0.685, p = 0.390, respectively). There were no significant differences in preoperative (p = 0.398) or postoperative (p = 0.546) side-to-side differences of anterior stability between Groups S and N. CONCLUSIONS: Segond fractures were confirmed in 4.1% of the cases on CT scans among patients undergoing primary ACL reconstruction. Segond fractures did not affect preoperative or 2-year follow-up evaluations of knee stability. From these results, we concluded that Segond fractures did not affect the clinical outcomes of the primary ACL reconstruction and that it may not be necessary to treat Segond fractures.

The difficulty of continuing sports activities after open-wedge high tibial osteotomy in patient with medial knee osteoarthritis: a retrospective case series at 2-year-minimum follow-up.

PURPOSE: This study aimed to investigate the rate at which patients returned to sports after open wedge high tibial osteotomy and identify the continuity of sports activity post-operatively. METHODS: Thirty-five patients (40 knees) who underwent open-wedge high tibial osteotomy (OW-HTO) in medial knee osteoarthritis were included in this study. The mean age of the patients who underwent surgery was 55.1 ± 10.7 years, and the mean follow-up period was 41.0 ± 24.7 months. Clinical results and radiographic parameters calculated in standing whole-leg radiographs preoperatively, post-operatively, and at the final follow-up were evaluated. RESULTS: Thirty-one patients (88.6%) were able to return to preoperative sports activity; however, only 14 patients (40.0%) completely returned to preoperative sports activity levels. Of the 31 patients who returned to sports activity, 10 patients (32.3%) maintained post-operative sporting activity levels at the final follow-up. In radiographic parameters, the weight-bearing line ratio was considered loss of correction in the post-operative period leading to the final follow-up. Patients who completely returned to sports and maintained sporting activity levels at the final follow-up had significantly higher the Knee Injury and Osteoarthritis Outcome Score pain subscale values and lower visual analogue scale of knee pain at pre-surgery and final follow-up than other patients, including those who partially returned to sports. CONCLUSIONS: The proportion of patients who returned to sports after OW-HTO and were able to participate in competitions at the same activity level as before surgery was low and insufficient. LEVEL OF EVIDENCE: Retrospective case series, IV.

Association Between Osteochondritis Dissecans of the Humeral Capitellum and Medial Epicondyle Lesion in Baseball Players.

BACKGROUND: Osteochondritis dissecans (OCD) of the humeral capitellum occurs in adolescent overhead athletes, and medial epicondyle (ME) lesions are also common in this population. PURPOSE: To evaluate the association between elbow OCD and ME lesions in adolescent baseball players. STUDY DESIGN: Cross-sectional study; Level of evidence, 3. METHODS: This study retrospectively evaluated adolescent baseball players with unstable elbow OCD who underwent surgery between January 2000 and February 2020. Patients were excluded if they had osteoarthritis of the elbow. A total of 139 elbows were included in this study (138 male and 1 female athlete; mean ± SD age, 13.6 ± 1.5 years). The patients were first divided into 2 groups based on OCD location: a central lesion group (72 elbows) and a lateral group (67 elbows). Next, patients were divided according to OCD size into a localized group (56 elbows) and a widespread group (83 elbows). Finally, OCD lesions that were both lateral and widespread were defined as lateral-widespread (60 elbows), resulting in 5 groups. ME apophyseal fragmentation and elongation were evaluated and defined as ME lesions. We then compared the relationship between OCD and ME lesions. RESULTS: Of the 139 elbows, 63 (45.3%) had ME lesions. The prevalence of ME lesion was higher in the lateral group than the central group (56.7% vs 34.7%; P = .009) and higher in the widespread group than the localized group (55.4% vs 30.4%; P = .004). Furthermore, the prevalence ratio of ME lesion was significantly higher in the lateral-widespread group than for other lesions (58.3% vs 35.4%; P = .007). CONCLUSION: In patients undergoing surgery for capitellar OCD, the presence of ME lesions was more commonly associated with lateral and widespread capitellar lesions when compared with central and localized lesions.

US detection of medial meniscus extrusion can predict the risk of developing radiographic knee osteoarthritis: a 5-year cohort study.

OBJECTIVES: To clarify the relationship between the baseline value of medial meniscus extrusion (MME) and the radiographic change of knee osteoarthritis (KOA) through a 5-year follow-up. METHODS: Overall, 472 participants and 944 knees were eligible. MME (mm) was measured at the baseline, and KOA was radiographically evaluated at both baseline and 5-year follow-up by Kellgren-Lawrence grade (KLG). Radiographic KOA (ROA) was defined as the knee showing KLG ≥ 2. Incident ROA (iROA) was defined if the baseline KLG of 0-1 increased to KLG ≥ 2 in 5 years. Progressive ROA (pROA) was defined if the baseline KLG of 2-3 worsened to a higher grade in 5 years. Receiver operating characteristic (ROC) curve and generalized estimating equations were used for analysis. RESULTS: Of 574 non-ROA knees at the baseline, 43 knees (7.5%) developed iROA; of 370 ROA knees, 47 knees (12.7%) developed pROA. Based on the ROC curves, 4 mm was the optimal cutoff to detect the risk of iROA (area under curve [AUC] 0.639 [right knee]; AUC 0.641 [left knee]) and that of pROA (AUC 0.750 [right knee]; AUC 0.863 [left knee]). Multiple regression analysis showed that the 4-mm cutoff of MME was significantly associated with both the prevalence of iROA (regression coefficient [B] 1.909; p ≤ 0.001; adjusted odds ratio [aOR] 6.746) and that of pROA (B 1.791; p ≤ 0.001; aOR 5.993). CONCLUSIONS: On ultrasonography, the participants with more extruded medial meniscus showed a higher prevalence of both iROA and pROA. Ultrasonography could identify patients who had a risk of developing KOA. KEY POINTS: • Through a 5-year follow-up, the current cohort study was conducted to clarify the relationship between the baseline value of medial meniscus extrusion (MME) and the radiographic change of knee osteoarthritis (KOA). • More extruded medial meniscus evaluated by ultrasonography was associated with the development of radiographic KOA. • Ultrasonography could identify the patients who had a risk of developing KOA, and the 4-mm cutoff of MME was optimal to detect this risk.

Core-Muscle Training and Neuromuscular Control of the Lower Limb and Trunk.

CONTEXT: Comprehensive injury-prevention training (plyometric, agility, balance, and core-stability exercises) has been shown to decrease sport-related injury. The relationship between trunk control and sport-related injury has been emphasized; however, the isolated effects of core-muscle training are unclear. OBJECTIVE: To investigate the effect of a simple 8-week core-muscle-training program on the neuromuscular control of the lower limb and trunk during jump landing and single-legged squatting. DESIGN: Controlled laboratory study. SETTING: Laboratory. PATIENTS OR OTHER PARTICIPANTS: Seventeen female collegiate basketball players were randomly divided into training (n = 9; age = 19.7 ± 0.9 years) and control (n = 8; age = 20.3 ± 2.5 years) groups. INTERVENTION(S): The training group completed the core-muscle-training program in addition to daily practice, and the control group performed only daily practice. Kinematic and kinetic data during a drop-jump test and single-legged squat were acquired using a 3-dimensional motion-analysis system. MAIN OUTCOME MEASURE(S): Three-dimensional hip, knee, and trunk kinematics; knee kinetics; and isokinetic muscle strength were measured at the pretraining and posttraining phases. RESULTS: For the drop-jump test, the maximal trunk-flexion angle increased (P = .008), and peak knee-valgus moment (P = .008) decreased in the training group. For the single-legged squat, the peak trunk-flexion angle increased (P = .04), and the total amount of trunk lateral-inclination angle (P = .02) and peak knee-valgus moment (P = .008) decreased in the training group. We observed no changes in the control group. CONCLUSIONS: A consecutive 8-week core-muscle-training program improved lower limb and trunk biomechanics. These altered biomechanical patterns could be favorable to preventing sport-related injuries.

Greater Laxity in the Anterior Cruciate Ligament-Injured Knee Carries a Higher Risk of Postreconstruction Pivot Shift: Intraoperative Measurements With a Navigation System.

BACKGROUND: The presence of pivot shift after anterior cruciate ligament (ACL) reconstruction is correlated with worse clinical outcomes. An orthopaedic navigation system is a useful tool for quantifying laxity in the ACL-deficient knee. PURPOSE: To investigate the relationship between preoperative knee laxity measured by a navigation system and postoperative pivot shift (PPS) after ACL reconstruction. STUDY DESIGN: Case-control study; Level of evidence, 3. METHODS: One hundred patients who underwent primary ACL reconstruction (62 hamstring tendon grafts, 38 patellar tendon grafts) were grouped according to the presence or absence of pivot shift at the 2-year follow-up, and the groups were compared retrospectively. Before surgery, knee laxity was assessed with a navigation system to quantify posterior tibial reduction (PTR) during pivot-shift tests and anterior tibial translation (ATT) during Lachman tests. PTR and ATT cutoff values were determined by receiver operator characteristic (ROC) analysis. RESULTS: Preoperative PTR and ATT were significantly larger for patients with PPS (PPS-positive group) than those without (PPS-negative group). In the ROC analysis, the PTR had an area under the curve of 0.871 (95% CI, 0.763-0.979; P < .0001) for predicting a PPS; this was larger than that obtained for the ATT, which had an area under the curve of 0.825 (95% CI, 0.705-0.946; P = .001). Because the ROC curve of the ATT had 2 peaks, the ATT alone was not a suitable predictor for PPS. Based on the ROC curve, the optimal PTR cutoff value was 7 mm, with 88.9% sensitivity and 71.4% specificity for PPS (adjusted odds ratio = 19.7; 95% CI, 2.1-187.9; P = .009). Setting the cutoff value as a combination of the PTR (≧7 mm) and ATT (≧12 mm) improved the specificity (88.9% sensitivity and 84.6% specificity; adjusted odds ratio = 149.8; 95% CI, 5.9-3822.7; P = .002) over that with the PTR alone. CONCLUSION: ACL injuries in knees with a large PTR had a higher risk of PPS. When reconstructing the ACL in a knee with a high degree of laxity, surgeons may need to adopt strategies to prevent PPS.

Characteristics of elongated and ruptured anterior cruciate ligament grafts: An analysis of 21 consecutive revision cases.

BACKGROUND/OBJECTIVE: Anterior cruciate ligament (ACL) reconstructions often fail without graft rupture. The purpose of this study was to compare the characteristics of patients with elongated and ruptured bone-patellar tendon-bone (BTB) grafts that required revision surgery. METHODS: Twenty one patients who required revisions of a BTB-reconstructed ACL between 2010 and 2015 were enrolled in this study. All patients were evaluated for bone tunnel position using computed tomography. Tunnel angle was calculated with radiographs. Stability under anaesthesia, and meniscus and cartilage condition were evaluated during the revision surgery. Age at primary surgery, time between primary and revision surgery, activity level, original tunnel position of the graft, and meniscus and cartilage condition were compared between elongated and ruptured grafts. RESULTS: Age at primary surgery was not significantly different between the two groups (p = 0.528). Time between primary and revision surgery as well as activity level were also not significantly different between the two groups (p = 0.010 and p = 0.307, respectively). Femoral bone tunnel position was more proximal (p = 0.003), and radiographic tunnel angle was not significantly different between the two groups (p = 0.029). The rupture group was significantly more unstable on the pivot shift (p < 0.003). Meniscus degeneration, meniscus tear, and cartilage damage were not significantly different between the two groups (p = 0.030, p = 0.311, and p = 0.505, respectively). CONCLUSION: The location of the original femoral tunnel was more proximal in patients with elongated grafts than in those with ruptured grafts. Different bone tunnel position from native ACL might lead to graft elongation.

Meniscal extrusion seen on ultrasonography affects the development of radiographic knee osteoarthritis: a 3-year prospective cohort study.

The objective of this study is to determine whether meniscal extrusion (ME) of the medial meniscus on ultrasonography affects knee osteoarthritis (KOA) progression during 3-year follow-up. Two hundred seventy volunteers (70 men, 200 women; mean age 60.5 years) participated. Weight-bearing radiographs were evaluated. All subjects had medial radiographic KOA (Kellgren-Lawrence grade [KLG], ≥ 2) in at least one knee at baseline (BL). KLG 2 was defined as moderate KOA (MKOA); KLG 3 and 4 were defined as severe KOA (SKOA). Medial and lateral joint space width (MJSW and LJSW) were measured at the minimum width of femoro-tibial compartment. The medial and lateral osteophyte area (MOPA and LOPA) were measured. Rapid joint space narrowing progression (RP) was defined as ≥ 25% loss of JSW from BL. ME was measured at the medial knee joint space on the medial collateral ligament with ultrasonography. The optimal ME cut-off for RP was determined by ROC curve. The relationship between ME and the longitudinal change of radiographic parameters was elucidated by linear and logistic regression analysis. In the 460 OA knees at BL, both MOPA and LOPA increased, while only MJSW narrowed after 3 years. RP occurred in 25 knees among 281 MKOA knees and 42 among 179 SKOA knees. ME was associated with medial joint space narrowing only in the SKOA group, while the ME was associated with MOPA in the MKOA and SKOA groups. The cut-off value to detect RP was 5.5 mm only in the SKOA group. Ultrasonographic evaluation of medial ME was useful to detect radiographic KOA progression.

Evaluation of a quantitative measurement of suprapatellar effusion by ultrasonography and its association with symptoms of radiographic knee osteoarthritis: a cross-sectional observational study.

BACKGROUND: Quantitative measurement of knee joint effusion by ultrasonography has not been well established; however, a categorical measurement (e.g., a ≥4-mm-deep suprapatellar pouch) is recommended. Therefore, the current study aimed to elucidate the association between symptoms of knee osteoarthritis (OA) and the quantitative measurement of suprapatellar effusion by ultrasonography. METHODS: One hundred twenty-seven volunteers participated (31 men and 96 women; mean age: 68.3 ± 9.8 years; body mass index: 23.2 ± 3.0 kg/m(2)). The Kellgren-Lawrence grades (KLGs) of both knees were assessed; all subjects had definitive osteoarthritic change (KLG ≥2) in both knee joints. Joint effusion was evaluated using an ultrasound probe, which was placed longitudinally on the suprapatellar pouch, and we determined the area (mm(2)) of the echo-free space. Then we summed the effusion area of both knees. All subjects answered the knee injury and osteoarthritis outcome scale (KOOS) questionnaire. Multiple linear regression analysis was conducted to elucidate the association between the summed value of the knee effusion area and the KOOS subscales, which were adjusted by age, sex, body mass index, and KLG. RESULTS: Of 254 knees, 180 were KLG 2, 57 were KLG 3, and 17 were KLG 4. The multiple regression models showed that the quantitative knee effusion area significantly correlated with the following KOOS subscales: pain (B = -0.057; ß = -0.253; P = 0.002), symptom (B = -0.053; ß = -0.251; P = 0.002), sport and recreation (B = -0.069; ß = -0.205; P = 0.007), and quality of life (B = -0.083; ß = -0.276; P = 0.001). CONCLUSION: In this cross-sectional study, the quantitative measurement of suprapatellar effusion by ultrasonography was associated with symptoms of radiographic knee OA.

Quantification of the pivot-shift test using a navigation system with non-invasive surface markers.

PURPOSE: The purpose of this study was to validate the quantitation of the pivot-shift phenomenon by using a navigation system with non-invasive surface markers. Measurements obtained using this system were compared with those obtained using commercial pin-fixed markers. METHODS: Seventy patients with anterior cruciate ligament (ACL) injuries were assessed under general anaesthesia. Knee kinematics during the pivot-shift test were recorded using an image-free navigation system with a commercial transmitter placed on the thigh and lower leg (surface markers) or those fixed to the femur and the tibia via metal pin fixators (pin-fixed markers). For quantitation of the pivot-shift phenomenon, posterior tibial reduction (PTR) was calculated using the two types of navigation system markers and were then compared. PTRs measured using the two types of markers were also compared with clinical grade of the pivot-shift test, as determined by an examiner. RESULTS: The pivot-shift phenomenon could be identified in all patients on the navigation screen. The PTR measured using surface markers moderately correlated with that measured using pin-fixed markers (ρ = 0.524, p < 0.001). There were also moderate correlations between clinical grades and the PTRs measured using either the surface markers (ρ = 0.522, p < 0.001) or the pin-fixed markers (ρ = 0.645, p < 0.001). CONCLUSIONS: The present study demonstrated that PTR, during the pivot-shift test, may be quantified in ACL-injured knees, using a navigation system with surface markers, and that the PTR measured with surface markers moderately correlated both with the PTR obtained using pin-fixed markers and with the clinical grade of the pivot-shift test. A customised method of fixing transmitters with reflective markers to patients' thighs and shins with Velcro straps is non-invasive and could assess and record the knee kinematics, especially the pivot-shift test, in ACL-injured and ACL-reconstructed knees before, during, and after surgery using a navigation system. LEVEL OF EVIDENCE: Case series, Level IV.

Prospective Randomized Study of Objective and Subjective Clinical Results Between Double-Bundle and Single-Bundle Anterior Cruciate Ligament Reconstruction.

BACKGROUND: There is controversy as to whether double-bundle anterior cruciate ligament (ACL) reconstruction with hamstring tendon graft (DB-HT) or single-bundle ACL reconstruction with patellar tendon graft (SB-PT) obtains the best clinical outcomes. PURPOSE: To compare the short-term clinical outcomes of DB-HT with those of rectangular-tunnel SB-PT (RTSB-PT) at 2-year follow-up and to identify the factors that affect subjective knee functional score. STUDY DESIGN: Randomized controlled trial. Level of evidence, 1. METHODS: Sixty-three male patients (mean age, 26.1 years) and 87 female patients (mean age, 25.8 years) were included in this study and were randomly distributed to either the DB-HT (n = 76) or RTSB-PT (n = 74) group. Clinical outcomes (knee flexion range of motion [ROM], heel-height difference, side-to-side difference in anterior laxity, rotational laxity, and Tegner activity score) were compared between the DB-HT and RTSB-PT groups, and examination of factors affecting subjective outcomes (Knee Injury and Osteoarthritis and Outcome Score [KOOS] results) was performed by multiple linear regression analysis. RESULTS: Fourteen patients (9 DB-HT, 5 RTSB-PT) had secondary ACL injury within 2 years after primary ACL reconstruction and were excluded from analysis. In the examination of 136 patients at the 24-month follow-up, there was no significant difference between the 2 groups in clinical or subjective outcomes. The normalized knee extensor strength of the RTSB-PT group showed negative surgical technique effect in the early postoperative phase (P = .005), but there was no significant difference between the 2 groups at the 24-month follow-up (P = .114). There was no significant difference in change of normalized knee flexor strength between the 2 groups (P = .493). Age, sex, body mass index (BMI), and presence of meniscus injury were the factors that affected KOOS subscale scores. CONCLUSION: In this prospective randomized controlled study, there was no significant difference in the incidence of secondary ACL injury and no difference in objective or subjective outcomes between the DB-HT and RTSB-PT reconstruction at 24-month follow-up. Age, sex, presence of meniscus injury, and BMI affected subjective KOOS subscale scores, while surgical technique did not.

The Knee injury and Osteoarthritis Outcome Score reflects the severity of knee osteoarthritis better than the revised Knee Society Score in a general Japanese population.

PURPOSE: The purposes of this study were to examine population-based reference data for sex- and age-related differences between the 2011 revised Knee Society Score (KSS2011) and the Knee injury and Osteoarthritis Outcome Score (KOOS), to assess the correlation between those scores and radiographic knee osteoarthritis (OA), and to validate the use of the scores in a general Japanese population. METHODS: This cross-sectional study included 963 volunteers (368 males, 595 females; mean age: 54.7years). Participants were classified into five subgroups by age: under 40, 40s, 50s, 60s, and over 70years old. The KSS2011 and KOOS were determined using self-administered questionnaires. Weight-bearing radiographs of the bilateral knee were taken and graded according to the Kellgren-Lawrence (KL) scale. The mean KSS2011 and KOOS were compared among age groups. Correlations between the severity of knee OA and each score were assessed using multiple regression analysis. RESULTS: The overall KSS2011 tended to gradually decrease with age. Most subscales of the KSS2011 did not show sex-related differences. Similarly, the overall KOOS and all its subscales steadily decreased by approximately 20 points per decade with age. Most subscales of the KOOS were significantly decreased in females over 50. The KL grade was significantly related to both the overall KOOS (ß=-0.42, p<0.001) and KSS2011 (ß=-0.13, p=0.001), though the correlation to the KOOS was stronger. CONCLUSION: The overall KSS2011 and KOOS appear to decrease with age. In this population, the KOOS reflects the severity of knee OA better than the KSS2011.

Hyaluronic acid induces the release of growth factors from platelet-rich plasma.

BACKGROUND/OBJECTIVE: Platelet-rich plasma (PRP) and hyaluronic acid (HA) injection are both therapeutic options for osteoarthritis and chronic tendinopathy. Although several comparative studies on the two have been published, the effects of mixing PRP and HA are not fully understood. The purpose of this study is to investigate the influence of HA on platelets in PRP by measuring releasing growth factors. METHODS: PRP was produced from nine healthy adult volunteers (mean age, 32.8 ± 2.9 years; range, 29-37) with a commercial separation system. HA of weight-average molecular weight of 50-120 kDa was used. PRP group (PRP 1 mL + phosphate buffered saline 0.2 mL) and PRP + HA group (PRP 1 mL + HA 0.2 mL) were incubated at 37°C for 2 hours. The amounts of transforming growth factor ß1 (TGF-ß1) and platelet-derived growth factor (PDGF-AA) released from the PRP and PRP + HA samples were measured on Day 0, Day 3, and Day 5. In addition, the same growth factors on Day 5 were measured for PRP + high HA group (PRP 1 mL + HA 0.6 mL) with five donors. After collecting all of the samples on Day 5, the remaining gels were observed with Giemsa stain. Statistical analyses were performed using paired t tests to compare the PRP and HA groups at each time point, and a one-way analysis of variance (one-way ANOVA) with Tukey post hoc tests was used to compare the PRP, PRP + HA, and PRP + high HA groups. RESULTS: The TGF-ß1 concentrations in the PRP and PRP + HA were 24.3 ± 7.2 µg/mL and 22.4 ± 1.8 µg/mL (p = 0.689) on Day 0, 17.2 ± 13.9 µg/mL and 25.4 ± 7.1 µg/mL (p = 0.331) on Day 3, and 12.7 ± 10.5 µg/mL and 33.7 ± 8.3 µg/mL (p = 0.034) on Day 5. The TGF-ß1 concentrations on Day 5 were 24.1 ± 5.2 µg/mL (PRP group), 28.3 ± 2.4 µg/mL (PRP + HA), and 31.9 ± 4.8 µg/mL (PRP + high HA; one-way ANOVA: p = 0.003; post hoc PRP vs. PRP + HA: p = 0.016). The PDGF-AA concentrations in the PRP and PRP + HA groups were 2.30 ± 1.21 µg/mL and 2.32 ± 0.79 µg/mL (p = 0.931) on Day 0, 2.03 ± 0.53 µg/mL and 2.13 ± 0.73 µg/mL (p = 0.500) on Day 3, and 1.51 ± 0.40 µg/mL and 2.00 ± 0.52 µg/mL (p = 0.003) on Day 5. The PDGF-AA concentrations were 1.48 ± 0.46 µg/mL (PRP group), 1.94 ± 0.57 µg/mL (PRP + HA), and 2.69 ± 0.70 µg/mL (PRP + high HA; one-way ANOVA: p = 0.0002; PRP vs. PRP + high HA: p = 0.002; PRP + HA vs. PRP + high HA: p = 0.011) on Day 5. The PRP showed larger coagulated masses than the PRP + HA. The high concentration HA group had the smallest coagulated mass of all of the group. CONCLUSION: The levels of growth factors released by PRP on Day 5 were increased by the addition of HA. A mixture of PRP and HA may be a more effective therapy than PRP or HA alone for osteoarthritis and tendinopathy.

Serum hyaluronic acid concentration predicts the progression of joint space narrowing in normal knees and established knee osteoarthritis - a five-year prospective cohort study.

INTRODUCTION: Serum hyaluronic acid (sHA) is a serum biomarker for knee osteoarthritis (OA). Although sHA concentration is elevated in patients with knee OA, the relationship between serum concentration and disease progression remains unclear. We examined the relationship between sHA concentration and radiographic progression of knee OA in a cohort of individuals followed for 5 years. METHODS: We prospectively enrolled 444 individuals and measured their sHA concentrations at baseline. Anterior-posterior weight bearing knee radiographs were obtained at baseline and the 5-year endpoint. Osteoarthritic knee changes were classified according to Kellgren-Lawrence (KL) grade, and joint space narrowing (JSN) was measured using a Knee Osteoarthritis Computer-Aided Diagnosis (KOACAD) system. Correlations between sHA concentration, progression in KL grade, and JSN were assessed using regression models, taking into account potentially confounding factors. RESULTS: OA progressed from KL grades 0 or 1 in 129 of the 323 knees, and from KL grades 2 or 3 in 61 of the 119 knees. Higher sHA concentrations were correlated with KL grade progression (p = 0.004). The mean JSN, as assessed by KOACAD over 5 years, was 0.23 ± 0.55 mm, and sHA concentration was positively correlated with progression of JSN in KL grades 0 or 1 (p = 0.021) and KL grades 2 or 3 (p = 0.008) knees. CONCLUSION: Serum HA concentration was positively correlated with progression of KL grade. sHA was also positively correlated with progression of JSN in knees with and without OA, suggesting that sHA concentration may be a useful predictor of knee OA progression.

Histological evaluation of low-intensity pulsed ultrasound on osteochondritis dissecans of the humeral capitellum.

BACKGROUND: The clinical use of low-intensity pulsed ultrasound (LIPUS) was recently evaluated in cases of osteochondritis dissecans of the humeral capitellum (elbow OCD). However, the mechanism underlying the effect of LIPUS in elbow OCD is not well understood. The aim of this study was to histopathologically evaluate the effect of LIPUS irradiation on elbow OCD. METHODS: Fifteen patients with elbow OCD were enrolled in this study. All patients were juvenile baseball players (average age, 13.1 years). LIPUS was performed under the same conditions as the fracture treatment for an average length of 15.1 days in the preoperative period in seven patients (LIPUS group). Cylindrical tissue specimens obtained at the time of surgery were stained with hematoxylin and eosin and alcian blue, and were also immunostained to detect type 1 collagen (Col-1), osteopontin (OPN), and Runx2. The state of the cartilage and subchondral bone and expression levels of Col-1, OPN, and Runx2 were evaluated with a semiquantitative grading system by a blinded pathologist. Histological and immunohistological findings in both groups were compared using Fisher's exact test. RESULTS: Both groups showed reparative tissue and cartilaginous metaplasia at the separation level near the subchondral bone; Col-1 was expressed in the reparative tissue. Furthermore, OPN and Runx2 were expressed in the interstitial cells near the separation level. The cartilage and subchondral bone findings in histological evaluations did not differ significantly between the LIPUS and control groups. The distribution of OPN expression levels in the two groups was as follows: Grade 0-LIPUS group, zero patients, and control group, five patients; Grade 1-LIPUS group and control group, two patients each; Grade 2-LIPUS group, five patients and control group, one patient; Grade 3-LIPUS group, one patient and control group, zero patients. OPN expression was significantly higher in the LIPUS group than in the control group (p = 0.04). CONCLUSION: LIPUS stimulation increased the expression levels of OPN in elbow OCD.

Intraoperative laxity measurements using a navigation system in anatomical double-bundle posterior cruciate ligament reconstruction.

PURPOSE: The objective of this study was to evaluate knee kinematics during double-bundle posterior cruciate ligament reconstruction (DB-PCLR) intraoperatively using a navigation system, and especially assess biomechanical behaviour of the anterolateral bundle (ALB) and posteromedial bundle (PMB) graft in DB-PCLR. Also, clinical results of minimum 2-year follow-up were investigated. METHODS: Nine patients received DB-PCLR with hamstring graft. Before reconstruction, knee laxities, including posterior tibial translation (PTT) in neutral rotation at 15°, 30°, 45°, 60°, 75° and 90° of knee flexion, were measured using a kinematic-based navigation system. After the PMB or ALB was temporally fixed, the knee laxities were measured in the same manner. Each patient was evaluated pre- and post-operatively with side-to-side difference of tibial position in gravity sag view and Lysholm score. RESULTS: Both ALB and PMB fixation restrained the PTT compared to  PCL deficiency throughout all knee flexion angles. At 90° of knee flexion, ALB fixation significantly decreased PTT compare to PMB fixation (p = 0.014) and DB-PCLR significantly decreased PTT compare to ALB fixation (p = 0.045). The mean side-to-side difference of tibial position in gravity sag view was 12.0 ± 1.7 mm preoperatively and 2.3 ± 1.8 mm at final follow-up, and the mean Lysholm scores were 68.9 ± 20.9 and 96.3 ± 2.9, respectively. CONCLUSIONS: There were no significant differences in the PTT between ALB and PMB fixations at 0° to 75° of knee flexion, and both ALB and PMB reconstructions are important for restraining PTT. At 90° of knee flexion, the ALB grafts may be more important to control PTT compared to PMB grafts; however, neither single-bundle reconstruction with ALB nor PMB could function as DB-PCLR did. In addition, PTT after DB-PCLR was strongly correlated side-to-side difference in posterior sag view at the final follow-up. The results from this study indicated that both ALB and PMB are important to stabilize PCL-deficient knees. LEVEL OF EVIDENCE: Therapeutic study, Level III.

Nocturnal knee pain increases with the severity of knee osteoarthritis, disturbing patient sleep quality.

OBJECTIVE: Sleep disturbances frequently accompany chronic pain from osteoarthritis (OA). Effective management of sleep disturbances may require successful treatment of chronic pain, a key factor in the clinical evaluation of knee OA. However, the relationship between the severity of knee OA and sleep quality is unclear. Our purpose was to correlate the prevalence of nocturnal knee pain with different OA severity levels and to determine its influence on sleep quality. METHODS: Subjects included 1,214 local volunteers with mean ± SD age 58.1 ± 13.0 years. The existence and severity of knee OA were determined by the Kellgren/Lawrence (K/L) grade, and joint space widths were measured. The presence of nocturnal knee pain and Knee Injury and Osteoarthritis Outcome Scores (KOOS) were assessed by self-completed questionnaires. Sleep quality was evaluated by the Pittsburgh Sleep Quality Index. Knee-related factors affecting sleep quality were detected using statistical methods. RESULTS: The prevalence of nocturnal knee pain was 3.6%, 6.9%, 19.4%, 32.7%, and 75.0% in K/L grades 0, 1, 2, 3, and 4, respectively. Also, prevalence significantly increased with OA severity (P < 0.001). Sleep problems also increased with K/L grade (P = 0.038), and KOOS quality of life (QOL) was significantly lower in those with OA and sleep problems. Logistic regression showed that sleep problems were related to joint space narrowing (P = 0.016) and nocturnal knee pain (P = 0.039). Severe OA also disturbed onset and maintenance of sleep. CONCLUSION: The prevalence of nocturnal knee pain and sleep problems increased with the severity of OA, impacting QOL. These results suggest the necessity of appropriate nocturnal pain control.

Change with increasing age in control of the lower limbs during jump-landing in adolescents: a 5-year prospective study.

BACKGROUND: A discrepancy in the incidence of anterior cruciate ligament injury in males and females appears after puberty; however, little is known about changes that occur in control of the lower limbs during jump-landing in adolescents. METHODS: Twenty-five male and 29 female 5th grade students (age 10-11 years) participated at the beginning of study and were followed for 5 consecutive years. Control of the lower limbs during jump-landing was evaluated by use of a drop-jump test and 2-dimensional video analysis. The K/H ratio, which was determined by dividing the knee-separation distance by the hip-separation distance, was calculated for initial contact (IC) and for maximum knee flexion (MKF). RESULTS: In all grades female subjects had a significantly lower K/H ratio at both IC and MKF than male subjects. Although no statistically significant difference in K/H ratio between age categories was shown at either IC or MKF for male subjects, K/H ratio at IC and MKF decreased significantly between 5th grade and 9th grade for female subjects. CONCLUSION: This study suggests that adolescent females have a lower K/H ratio during jump-landing than male subjects of the same age, and that K/H ratio for females decreases with increasing age.

The femoral insertion of the anterior cruciate ligament: discrepancy between macroscopic and histological observations.

PURPOSE: To observe the femoral anterior cruciate ligament (ACL) insertion macroscopically, histologically, and immunohistologically. METHODS: We used 20 embalmed cadaveric knees (mean age, 69.8 ± 5.3 years) for this study. The femoral ACL insertion was observed macroscopically, and areas were measured with digital calipers. The morphology of the ACL insertion was subsequently observed, and the areas were measured histologically and immunohistologically (stained for types I and III collagen). Finally, the macroscopic and microscopic measurements were compared. RESULTS: Macroscopically, in 16 knees, the proximal ACL fibers spread in a fanlike manner on the medial aspect of the lateral femoral condyle and the femoral insertion was oval. The lengths of the long and short axes of the insertion were 17.7 ± 2.7 mm and 4.6 ± 0.7 mm, respectively. Microscopically, the insertion was located just behind the lateral intercondylar ridge (resident's ridge) and could be divided into the direct and indirect insertions. The direct insertion was 5.3 ± 1.1 mm wide and did not continue to the posterior cartilage. The indirect insertion was located behind the direct insertion, and the posterior ACL fiber stained for type I collagen blended into the posterior cartilage on immunohistologic observations. Another bony ridge was found at the posterior margin of the direct insertion. The widths of the direct insertion were similar between microscopic and macroscopic measurements. CONCLUSIONS: The femoral ACL insertion observed macroscopically corresponded to the direct insertion observed microscopically. The posterior portion behind the lateral intercondylar posterior ridge was the indirect insertion microscopically and appeared membrane-like macroscopically. CLINICAL RELEVANCE: Findings from observation of the lateral intercondylar posterior ridge during arthroscopy and consideration of the distance from the posterior cartilage border may contribute to surgeons' decisions about femoral tunnel placement during anatomic ACL reconstruction.