Construction of a mineralized collagen nerve conduit for peripheral nerve injury repair.

A new nerve guidance conduits (NGCs) named MC@Col containing Type I collagen (Col) and mineralized collagen (MC) was developed, enhancing mechanical and degradation behavior. The physicochemical properties, the mechanical properties and in vitro degradation behavior were all evaluated. The adhesion and proliferation of Schwann cells (SCs) were observed. In the in vivo experiment, MC@Col NGC and other conduits including Col, chitosan (CST) and polycaprolactone (PCL) conduit were implanted to repair a 10-mm-long Sprague-Dawley rat's sciatic nerve defect. Histological analyses, morphological analyses, electrophysiological analyses and further gait analyses were all evaluated after implantation in 12 weeks. The strength and degradation performance of the MC@Col NGC were improved by the addition of MC in comparison with pure Col NGC. In vitro cytocompatibility evaluation revealed that the SCs had good viability, attachment and proliferation in the MC@Col. In in vivo results, the regenerative outcomes of MC@Col NGC were close to those by an autologous nerve graft in some respects, but superior to those by Col, CST and PCL conduits. The MC@Col NGC exhibited good mechanical performance as well as biocompatibility to bridge nerve gap and guide nerve regeneration, thus showing great promising potential as a new type of conduit in clinical applications.

Secondary Thumb Reconstruction via Ectopic Banking of Bony Phalanges From a Nonreplantable Amputated Thumb: A Follow-Up Study.

PURPOSE: This study aimed to evaluate the radiological and functional results of secondary thumb reconstruction via ectopic banking of bony phalanges from a nonreplantable amputated thumb. METHODS: Thumb reconstruction was performed using the bony phalanges from a nonreplantable amputated thumb that were ectopically banked in a subcutaneous pocket. A wraparound flap was harvested from the ipsilateral great toe and wrapped around the bone graft. After surgery, the results were assessed in terms of infection, range of motion, bone union of the graft, and signs of osseous resorption of the reconstructed thumb. RESULTS: Fifteen patients underwent secondary thumb reconstruction using this technique between January 2003 and October 2018. Ten patients were followed up for at least 6 months (6 months to 9 years) and were included in this study. All wraparound flap transfers were viable. No bone graft infection was observed. In the 6 cases in whom the interphalangeal joint was not fused, the interphalangeal joint motion ranged from 5° to 60° with an average of 35.0° ± 15.1°. The metacarpophalangeal joint motion ranged from 5° to 66°, with an average range of motion of 48.2° ± 23.6° for the cases in whom the joint was not fused. In 8 of the 10 patients, the time of bone ectopic banking was within 10 days. In these patients, bone union with no osseous atrophy was observed. In 2 patients whose phalanx was banked for more than a month, different degrees of bone resorption of the grafted phalanx were evident after transplantation, although no further treatment was required. CONCLUSIONS: Bony phalanges from a nonreplantable amputated thumb can be ectopically banked and used for secondary reconstruction of the thumb. The duration of banking before thumb reconstruction should be no more than 2 weeks. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic V.

Risk Factors for Patellar Clunk or Crepitation after Primary Total Knee Arthroplasty: A Systematic Review and Meta-analysis.

Patellar clunk and crepitation (PCC) have been reported as a consequence of primary total knee arthroplasty (TKA). The incidence and contributing factors have not been fully defined. We performed this systematic review to evaluate factors associated with PCC following primary TKA. We identified studies on PCC following TKA from an electronic search of articles in Medline, Embase and the Cochrane databases (dated up to May 2018). Eighteen studies altogether, including 600 cases of PCC within 8,131 TKAs, were included in the meta-analysis. Several factors including demographic, intraoperative, clinical variables, and radiographic measurements were pooled for meta-analysis. Among intraoperative and clinical variables, patients involved with patellar retention (odds ratio [OR] = 9.420; confidence interval [CI]: 5.770-13.070), lateral reticular release (OR = 2.818; CI: 1.114-7.125), and previous surgery (OR = 2.724; CI: 1.549-4.790) were more likely to having PCCs. Among radiographic measurements, increased anterior tibial offset (weighted mean difference [WMD] = 0.387; CI: 0.139-0.634), increased joint line changes (WMD = 1.325; CI: 0.595-2.055), and increased knee flexion angle (WMD = 3.592; CI: 1.811-5.374) were considered risk factors associated with PCC. Demographic factors (age, gender, body mass index [BMI], and diagnosis) and other reported radiographic measurements were not associated with PCCs. This study identified intraoperative variables (patellar retention and lateral reticular release), clinical variables (previous surgery), and radiographic measurements (increased anterior tibial offset, increased joint line changes, and increased postoperative knee flexion angle) that contribute to an increased risk for PCC. Modifiable factors (patellar retention and lateral reticular release) should be considered and addressed to limit the risk for PCC following TKA. Patients with conditions that may not be modifiable may benefit from counseling about their increased risks for PCC to limit potential dissatisfaction with their procedure.

Anterior-medial collateral ligament portal : easy access to the torn posteromedial horn of the medial meniscus.

The posteromedial horn of the medial meniscus is prone to injury, and repair of a tear in this portion of the medial meniscus is especially challenging for the arthroscopist. We present a novel technique that allows good management of the posterior horn of the medial meniscus, even in patients with tight medial compartments. This technique uses two standard portals (the anterolateral portal and the anteromedial portal) to conduct arthroscopic examination, and uses a third portal as the workhorse portal to manage the posterior region so that the posterior horn tear can be easily removed. This new third portal is named the anterior-medial collateral ligament portal, and is positioned anterior to the anterior rim of the medial collateral ligament. This three-portal technique decreases the difficulty associated with management of the posteromedial region in knees with tight medial compartments.

Evaluation of Trochlear Dysplasia Severity Using Trochlear Angle: A Retrospective Study Based on Computed Tomography (CT) Scans.

BACKGROUND Trochlear dysplasia is an important pathological factor in patellofemoral instability. Quantitative evaluation of the severity of trochlear dysplasia is rare and remains unclear. MATERIAL AND METHODS Computed tomography (CT) data on 136 knees (95 patients) with trochlear dysplasia in the case group and an age- and sex-matched cohort of 120 knees (70 patients) in the control group were collected for this retrospective study. All participants had undergone CT scans in the supine position. The trochlear angles (TA) formed by the posterior condylar line and the trochlear line were calculated and compared. The threshold for statistical significance was set at p<0.05. RESULTS The mean TA values were significantly greater in the case group compared to the control group independent of sex (p<0.01). The distribution of trochlear dysplasia of Dejour grades was type A n=34, type B n=31, type C n=40, and type D n=31. Except for types A and B, differences in the trochlear dysplasia grade between any 2 other types were statistically significant (p<0.01). CONCLUSIONS The technique of measuring TA is reproducible and accurate in patients with patellar instability and normal controls. The TA positively correlates with higher levels of trochlear dysplasia. This technique can help to evaluate and treat trochlear dysplasia in research as well as in clinical practice.

A biomechanical analysis of triangular medial knee reconstruction.

BACKGROUND: The purpose of this study was to evaluate and compare knee kinematics and stability following either triangular or anatomical reconstruction of the superficial medial collateral ligament (sMCL) and posterior oblique ligament (POL). METHODS: In a cadaveric model (12 knees), the stability and kinematics following two experimental sMCL and POL reconstructions were compared in sMCL- and POL-deficient knees versus normal knees. The first reconstruction was a triangular reconstruction of the sMCL and POL, while the second involved an anatomical reconstruction of the sMCL and POL. All knees were tested through four different states. The changes in valgus angles, external rotation, and internal rotation were measured in the normal and sMCL- and POL-deficient knees, as well as in the knees that had undergone the two different forms (triangular and anatomical) of reconstruction. RESULTS: After initial sectioning of the sMCL and POL, we observed significantly increased valgus rotation, external rotation, and internal rotation at all knee flexion angles (0°, 20°, 30°, 60°, 90°). Additionally, passive stability testing demonstrated a significant increase in tibial internal rotation following triangular reconstruction compared with anatomical reconstruction at knee flexion angles of 20° and 30°. A significant increase in internal rotation was present following triangular reconstruction compared with anatomical reconstruction at 20° (mean difference = 2.77) (P = 0.008) and 30° (mean difference = 0.99) (P < 0.001) of knee flexion. CONCLUSION: This study suggests that anatomical sMCL and POL reconstruction produces slightly better biomechanical stability than triangular reconstruction. However, triangular reconstruction may restore a near-normal knee joint is both less invasive and more practical.

Spine-shortening osteotomy for patients with tethered cord syndrome: a systematic review and meta-analysis.

Purpose Tethered cord syndrome (TCS) is the clinical manifestation of an abnormal stretch on the spinal cord, caused by several pathological conditions. Tethered cord release is the gold standard treatment for TCS. However, direct untethering carries potential risks of spinal cord injury, post-operative retethering, and CSF-related complications. Spine-shortening osteotomy (SSO) has recently been performed as an alternative technique to avoid these risks. We aimed to systematically review the literature on indications and outcome of SSO in TCS patients. Methods We searched PubMed, Embase, Google Scholar, and the Cochrane Library to identify all studies on SSO in TCS patients. We used random or fixed-effects models to calculate rates and 95% confidence intervals to establish the rates of clinical improvement in TCS patients performed with SSO. Sensitive analysis and metaregression were made to explore potential sources of heterogeneit. Results We identified six eligible surveys with a total population of 57. Rates ranged from 62 to 88% for neurological deficits improvement, 80-100% for motor function improvement, 60-96% for pain or numbness scores improvement, 13-67% for sensory function improvement, and 79-100% for urinary and bowel dysfunction improvement. We noted substantial heterogeneity in rate estimates for motor function and urinary and bowel dysfunction improvement (all Cochran's χ² significant at P < 0.001; I² = 78.11%, 95%CI 61-94%; 84.28%, 18-100%; respectively). Conclusion SSO is a safe and effective technique for TCS patients, especially in more challenging cases, such as complex malformations or revision surgery. However, future cohort studies and randomized studies with large numbers and the power to provide illumination for the surgical decision-making of TCS are warranted.

Different Factors Conduct Anterior Knee Pain Following Primary Total Knee Arthroplasty: A Systematic Review and Meta-Analysis.

BACKGROUND: A systematic review and meta-analysis was performed to investigate the risks associated with anterior knee pain (AKP) following primary total knee arthroplasty (TKA). METHODS: A computerized search was performed of the following databases: MEDLINE, Embase, and Cochrane Central (published prior to July 2017). A total of 37 studies, which included 1641 cases of AKP and 168,090 TKAs, were included in the meta-analysis. RESULTS: A subgroup analysis revealed that compared with those without the following medical conditions, patients who had an infrapatellar fat pad excision and more than 12 months of follow-up (odds ratio [OR] 12.58, 95% confidence interval [CI] 3.245-48.781) were more likely to have AKP after TKA. Circumpatellar electrocautery (>12 months: OR 0.50, 95% CI 0.326-0.760; ≤12 months: OR 0.59, 95% CI 0.408-0.867) and patellar resurfacing (OR 0.25, 95% CI 0.131-0.485) may decrease the risk of AKP. Other factors, including the prosthesis bearing type (mobile bearing or fixed bearing) and the approach (midvastus compared with the medial parapatellar approach), were not significant risk factors for AKP. CONCLUSION: The use of strategies such as patellar denervation and patellar resurfacing in primary TKA is recommended because they are safe and result in good clinical outcomes in preventing AKP. Caution should be taken when using an infrapatellar fat pad excision, because there is an increased risk of AKP at long-term follow-up (>12 months). Future studies should investigate these different strategies to confirm the underlying mechanisms and help prevent the occurrence of AKP after TKA. The timing of AKP onset remains unclear and requires further research.

Ratio of the tibial tuberosity-trochlear groove distance to the tibial maximal mediolateral axis: A more reliable and standardized way to measure the tibial tuberosity-trochlear groove distance.

BACKGROUND: Tibial tuberosity-trochlear groove distance(TT-TG) is a measurement to assist in the diagnosis and treatment of patellar instability, however it still has some limitations. Our study was to modify the accepted measurement method and seek a more reliable and standardized method. METHODS: The data of 65 healthy controls and 49 patients with bilateral patellar instability from 2010 to 2016 were collected and analyzed by CT. The TT-TG, tibial maximal mediolateral axis (MML), and their ratio [i.e., the modified-TT-TG (M-TT-TG)] were compared between the two groups. RESULTS: The MML (71.9±12.0 vs. 71.3±10.9) was not significantly different between the two groups (P>0.05). However, the TT-TG(18.1±6.0 vs. 13.1±2.9) and M-TT-TG (0.25±0.08 vs. 0.19±0.04) were significantly different between the two groups (P<0.05). A TT-TG of >15mm was found in 24.5% of healthy controls and 71.5% of patients. The healthy controls with a TT-TG of >15mm were compared with the patients; although no significant difference was found in the TT-TG (16.8±1.5 vs. 18.1±6.0), the healthy controls had a significantly larger MML (76.9±12.7 vs. 71.9±10.9) and significantly smaller M-TT-TG (0.22±0.04 vs. 0.25±0.08). A total of 53.1% of patients but only 6.9% of healthy controls had an M-TT-TG of >0.25. CONCLUSION: The M-TT-TG is a more reliable and standardized way to measure the effect of the TT-TG with the goal of reducing the false-positive rate associated with the standard measurement technique. The normal M-TT-TG ranges from 0.11 to 0.25, with an M-TT-TG of >0.25 being associated with patellofemoral malalignment. LEVEL OF EVIDENCE: III.

Comparison of Results Between Posterior Fossa Decompression with and without Duraplasty for the Surgical Treatment of Chiari Malformation Type I: A Systematic Review and Meta-Analysis.

BACKGROUND: Posterior fossa decompression without (PFD) or with duraplasty (PFDD) for the treatment of type 1 Chiari malformation (CM-1) is controversial. We thus performed a systematic review and meta-analysis of studies to assess the effect on clinical and imaging improvement, operative time, complications, and recurrence rate between PFD and PFDD in patients with CM-1. METHODS: We systematically searched PubMed, Embase, Cochrane, Web of Knowledge, and ClinicalTrials.gov for retrospective or prospective studies comparing PFD with PFDD. Our main end points were clinical and imaging improvement, operative time, complications, and recurrence rate. We assessed pooled data by use of a fixed-effects or random-effects model according to the between-study heterogeneity. RESULTS: Of 214 identified studies, 13 were eligible and were included in our analysis (N = 3481 patients). Compared with PFD, PFDD led to a mean greater increase in operative time than did PFD [standardized mean difference, -2.35; 95% confidence interval [CI], (-2.70 to -1.99)], a higher likelihood of clinical improvement in patients with syringomyelia (relative risk [RR], 0.70; 95% CI, 0.49-0.98), no increased RR of clinical improvement in patients without syringomyelia, no increased RR of imaging improvement, but an increased RR of cerebrospinal fluid-related complications (RR, 0.29; 95% CI, 0.15-0.58), cerebrospinal fluid leak, aseptic meningitis, pseudomeningocele, and a decreased likelihood of recurrence rate. CONCLUSIONS: PFDD can be an optimal surgical strategy because of its higher clinical improvement and lower recurrence rate in the patients with syringomyelia. In patients without syringomyelia, PFD can be a preferred choice because of its similar clinical improvement and lower costs. Future randomized studies with large numbers and the power to provide illumination for surgical decision making in CM-1 are warranted.

Lateral retinaculum plasty instead of lateral retinacular release with concomitant medial patellofemoral ligament reconstruction can achieve better results for patellar dislocation.

PURPOSE: To elucidate the outcomes of lateral retinaculum plasty versus lateral retinacular release with concomitant medial patellofemoral ligament (MPFL) reconstruction. METHODS: In a prospective study, 59 patients treated at our institution from 2012 to 2014 were included. The 59 patients were randomly divided into two groups. Group I included 27 patients who underwent lateral retinacular release and MPFL reconstruction. Group II included 32 patients who underwent lateral retinaculum plasty and MPFL reconstruction. All patients were followed up for at least 2 years and all assessments were performed both pre- and post-operation. Clinical evaluation consisted of the Kujala score, patellar medial glide test, and patellar tilt angle, patellar lateral shift, and congruence angle, measured on CT scan. RESULTS: Significant improvement was seen after surgery in both groups. The group of lateral retinaculum plasty achieved better results than the group of lateral retinacular release. No statistically significant differences were found in lateral patellar shift (ns) or congruence angle (ns) between the groups. There were significant differences in Kujala score (P < 0.05) patellar tilt angle (P < 0.05), and patellar medial glide test (P < 0.05) between the groups. CONCLUSIONS: MPFL reconstruction with lateral retinaculum plasty yielded better results than MPFL with lateral retinacular release. Postoperatively, medial and lateral function were restored, and patellar tracking was normal. Lateral retinaculum plasty is a new method that reduces the complications of lateral retinacular release for patellar dislocation. LEVEL OF EVIDENCE: II.

Medial Patellofemoral Ligament Reconstruction with Semi-Patellar Tunnel Fixation: Surgical Technique and Mid-Term Follow-Up.

BACKGROUND The present study aimed to describe a new safe and economical technique for medial patellofemoral ligament (MPFL) reconstruction with satisfactory clinical outcomes, and present the results of a four-year follow-up. MATERIAL AND METHODS Thirty-two patients with recurrent patella dislocation, who underwent MPFL reconstruction with two semi-patellar tunnels and hardware-free patellar fixation between 2011 and 2013, were included in the study. Patella stability was tested by an apprehension test preoperatively and at follow-up. Knee function was evaluated using the Kujala score, Lysholm score, and Crosby-Insall grading system. Patellar congruence angle and patellar tilt angle were measured using an axial computed tomography scan. Furthermore, objective feelings of patients and complications were recorded. RESULTS Thirty knees (30 patients) were followed for a minimum of 48 months. The apprehension test was positive in all patients preoperatively, but negative at follow-up. Kujala and Lysholm scores increased from 58.9±9.6 to 92.0±4.8 (p<0.001) and 53.3±5.6 to 91.6±3.5 (p<0.001), respectively, at the last follow-up. Seventeen patients were graded as excellent and 13 were graded as good by the Crosby-Insall grading system. The patellar congruence angle and patellar tilt angle also improved significantly. No patient experienced patellar re-dislocation, subluxation, or patella fracture. Most patients (93%) were satisfied with the surgery. CONCLUSIONS MPFL reconstruction with two semi-patellar tunnels and hardware-free patellar fixation was described and the study observations indicated it was a safe and economical surgical procedure for recurrent patella dislocation with satisfactory results. It could be an alternative surgery method for patients with patella recurrent dislocation.

Better 4-year outcomes for anterior cruciate ligament reconstruction with double-layer versus single-layer bone-patellar tendon-bone allografts.

PURPOSE: To evaluate the results of anterior cruciate ligament reconstruction using a double-layer bone-patellar tendon-bone (DBPTB) graft. METHODS: Between 2010 and 2011, 98 patients underwent anterior cruciate ligament reconstruction with an allograft. Forty-seven of these patients received a DBPTB allograft and 51 received a traditional monolayer BPTB graft. Outcomes were evaluated at the end of a minimum 4-year follow-up in both groups using KT 1000 arthrometer measurements, Lachman and pivot-shift tests, the International Knee Documentation Committee form, and Lysholm scores. RESULTS: One patient (1/47, 2 %) in the DBPTB allograft group and six patients (6/51, 12 %) in the traditional monolayer BPTB graft were lost during follow-up because of graft rupture (n.s.). The mean side-to-side differences in the DBPTB and monolayer BPTB graft groups 4 years post-operatively were significantly different at 1.4 ± 1.3 and 1.7 ± 1.6 mm, respectively (p < 0.05). The DBPTB group performed significantly better than the BPTB group on the Lachman test, International Knee Documentation Committee knee score, and Lysholm scores (p < 0.05). CONCLUSIONS: The DBPTB allograft group achieved better outcomes than the traditional BPTB allograft group regarding success rate, anterior stability, and knee function. LEVEL OF EVIDENCE: Level II.

Relationship between the Patellar Ridge and the Femoral Trochlea in the Patellar Tracking.

OBJECTIVE: To investigate the anatomic morphology of the patellar ridge and how it matches the femoral trochlea in patellar tracking. METHOD: We selected 40 volunteers, 20 males (age, 28 ± 5 years) and 20 female (age, 27 ± 6 years), who were completely asymptomatic with normal knee structures. We measured the right or left legs of volunteers, and the region from the distal femur to the tibial tuberosity was scanned by computed tomography (CT) with flexion at 0°, 30°, 60°, and 90°. CT data was reconstructed using image analysis software (Mimics). Variables such as the angle between the patellar ridge and patellar long axis, the tibial external rotation angle, as well as the best matching position between the patellar ridge and femoral trochlea at different knee flexion angles were measured. A single experienced orthopedic surgeon performed all the measurements, and the surgeon was blinded to the subject identifying information. We analyzed the differences between the various angles using a one-way analysis of variance. The differences between genders were analyzed using the t test. RESULTS: The intraclass correlation coefficient (ICC) values were greater than 0.81 for all measurements, and the ICC value is almost in perfect agreement. The angle between the patellar ridge and the patellar long axis was 11.13° ± 4.1°. The angle in male participants was 10.87° ± 4.5° and it was 12.09° ± 3.7° in female participants. There were significant differences between each angle (0°, 30°, 60°, and 90°). The angles between the patellar ridge and femoral trochlear groove did not greatly increase with the knee flexion. The tibial internal rotation angle also showed a gradually increase at knee flexion of 0°-60°, and a gradually decrease at 60°-90°. The best-fit point between the patellar ridge and femoral trochlear groove gradually increased along with the knee flexion. There were no significant differences between male and female participants at all angles ( P < 0.05). CONCLUSION: The anatomic morphology of the patellar ridge allows better matching between the patellar ridge and femoral trochlea during knee flexion, which is an important mechanism for the regulation of patellar tracking.