Comparison between single- and double-bundle anterior cruciate ligament reconstructions for knee with grade 2 medial collateral ligament injury.

ABSTRACT: This research discussed clinical outcomes of anterior cruciate ligament reconstruction accompanied by conservative treatment for grade 2 medial collateral ligament injury, and comparison was performed between double-bundle and single-bundle anterior cruciate ligament reconstruction.Clinical information was retrospectively collected for 41 cases suffering anterior cruciate ligament injuries accompanied by grade 2 medial collateral ligament injuries. Within 14 days after their injuries 22 cases received single-bundle anterior cruciate ligament reconstruction (SB group), while 19 were treated with double-bundle medial collateral ligament reconstruction (DB group). Physical statuses were estimated based on International Knee Documentation Committee (IKDC) and Lysholm scores, Lachman, pivot shift and manual valgus test, and range of motion (ROM), while side-to-side difference was estimated through KT 2000 arthometer.Anterior cruciate ligament reconstruction accompanied by conservative treatment showed significantly improved anteroposterior, rotational and valgus stability, and IKDC and Lysholm scores (in comparison to pre-operative status, P < .05). Incidence of pivot shift was dramatically lower in DB group (2/19) than in SB group (7/22 and 2/22; P = .028). No substantial dissimilarity existed between DB and SB groups either in Lachman and valgus tests, KT 2000, ROM, IKDC, or Lysholm scores.Anterior cruciate ligament reconstruction accompanied by conservative treatment could achieve outstanding stability and functional manifestations for cases facing anterior cruciate ligament injury accompanied by grade 2 medial collateral ligament injury. Moreover, double-bundle anterior cruciate ligament reconstruction is superior to single-bundle operation in treating rotational instability of the knee.Level of evidence: Retrospective comparative study, Level III.

Age-related Changes of Posterior Tibial Slope and Its Roles in Anterior Cruciate Ligament Injury.

Nearly all previous studies in posterior tibial slope (PTS) and anterior cruciate ligament (ACL) injuries ignored age-related changes, and the published data are inconsistent. The objective of this study was to reveal age-related changes of PTS and its roles in ACL injury. Data for 2618 lower limbs were included initially based on the availability of lateral radiographs and a suitable femoro-tibial angle. The final 1431 subjects were analyzed according to age, gender, side, and injury status. Student's t-tests, one-way analysis of variance, and curve fitting were used to analyze data. The PTS in males was greater than that in females in the 0-9 and 30-39-year-old groups, but this pattern reversed in the 40-49, 60-69, 70-79, and 80-89-year-old groups. The PTS was greater on the left side than on the right side in the 0-9, 10-19, 50-59, 60-69, and 80-89-year-old groups. The curve fitting for PTS demonstrated a trend of first decreasing and then increasing with aging. The PTS values differed significantly between knees with an ACL injury and those without in the 20-29, 30-39, and 40-49-year-old groups but not in the 50-59-year-old group. The PTS follows a trend of first decreasing and then increasing, and its role in ACL injury changes with advancing age. The higher PTS is only unrelated to the risk of ACL injury in age groups with a lower mean PTS value.

Intraoperative anthropometric measurements of tibial morphology: comparisons with the dimensions of current tibial implants.

PURPOSES: This study analyzed morphological differences in the resected proximal tibial surfaces of Chinese males and females undergoing total knee arthroplasty (TKA) and compared the measurements with the dimensions of five currently used tibial implants. METHODS: The mediolateral (ML), middle anteroposterior (AP), medial anteroposterior (MAP), and lateral anteroposterior (LAP) dimensions of the resected tibial surfaces of 976 Chinese TKA knees (177 male, 799 female) were measured. The ML/AP ratio of every knee was calculated. These morphological data were compared with the dimensions of five currently used tibial implants. RESULTS: The ML, AP, MAP, and LAP dimensions of the resected proximal tibias showed significant differences according to gender. Compared with currently used tibial implants, the smaller implants showed tibial ML undersizing and the larger implants showed tibial ML overhang. The ML/AP aspect ratio progressively decreased with increasing AP dimension in the resected proximal tibias, which contrasts with the relatively constant or increased (NexGen) aspect ratio in currently used tibial implants. Males showed a higher ML/AP aspect ratio than females for a given AP dimension. This indicates that for an implant with a given AP dimension, the tibial ML dimension tends to be undersized in males and to overhang in females. CONCLUSION: The results of this study may provide fundamental data for designing suitable tibial implants for use in the Chinese population, especially for design of gender-specific prostheses. LEVEL OF EVIDENCE: II.

Clinical features and prognosis of discoid medial meniscus.

PURPOSE: To evaluate the clinical manifestations and the outcome of surgical treatment of discoid medial meniscus. METHODS: Records of 13 patients with discoid medial meniscus were retrospectively reviewed for their epidemiology, clinical manifestations, operation methods, treatment outcome and radiographic characteristics. RESULTS: The 13 cases of discoid medial meniscal injury took up 1.5 ‰ of the overall meniscal injuries treated at our institute during the 44-year period. Patients presented with knee pain (13 patients), giving away (10 patients), swelling (9 patients) and snapping (9 patients). The most common physical signs were medial joint line tenderness (13 patients) and positive McMurray test (11 patients). Ten patients required total meniscectomy. There were excellent short-term results: the median Tegner score was 7, and the mean Lysholm score was 94.8 ± 2.4 at two-year follow-up. However, the long-term outcome was not as good with degenerative changes in the medial compartment of all the involved knees. CONCLUSION: The discoid medial meniscus is extremely rare. The clinical signs and symptoms of discoid medial meniscal injuries are similar to those of any other meniscal injury. No Wrisberg-ligament type abnormality was found. Meniscectomy for discoid medial meniscus produced promising short-term results and deteriorating long-term results with secondary degeneration of cartilage in the medial compartment. LEVEL OF EVIDENCE: Retrospective case series, Level IV.

[Measurement of bone tunnel width with computed tomography versus plain radiography after anterior cruciate ligament single-bundle reconstruction].

OBJECTIVE: To compare the measurements of bone tunnel width with computed tomography (CT) and plain radiography two years after anterior cruciate ligament single-bundle reconstruction. METHODS: Twenty patients underwent primary anterior cruciate ligament single-bundle reconstruction with hamstring autografts. There were 10 females and 10 males. Tibial and femoral bone tunnel widths were measured with CT and plain radiography at least two years post-operation. The average follow-up period was 26 months (range, 24-31). The tunnel measurements were taken at the widest point of tibial and femoral tunnels on sagittal and coronal CT and plain radiography perpendicularly to the longitudinal axis of tunnels. All data were statistically analyzed. RESULTS: The tibial tunnel width of one case decreased on CT while all others increased. The average tibial tunnel width on coronal plain radiography was 0.9 ± 0.6 mm (range, 0.3-2.2) larger than that on CT. And the average width on sagittal plain radiography was 0.9 ± 0.5 mm (range, 0.1-2.1) larger than that on CT. Both were statistically significant. All femoral tunnel widths increased, except in 2 cases. The average femoral tunnel widths on coronal and sagittal plain radiography were both significantly larger than those on CT. And the difference were 0.7 ± 0.6 mm (range, 0-1.7) and 0.9 ± 0.7 mm (range, 0.1-2.7) respectively. CONCLUSION: Bone tunnel measurements on plain radiography are significantly larger than those on CT after anterior cruciate ligament reconstruction.

Sex, age, and annual incidence of primary total knee arthroplasty: a university affiliated hospital survey of 3118 Chinese patients.

BACKGROUND: In recent years, the number of patients undergoing primary total knee arthroplasty in China has rapidly increased. However, the incidence of primary total knee arthroplasty is unknown. The purpose of this study was to investigate the sex, age and, annual incidence of primary total knee arthroplasty based on 3118 Chinese patients who underwent the procedure during the period of 2000 - 2011. METHODS: Total knee arthroplasties were performed on 511 males and 2607 females in our hospital during the period of 2000 - 2011. The sex, age, and annual incidence of primary total knee arthroplasty were evaluated. RESULTS: The annual incidence of primary total knee arthroplasty increased from 35 knees in 2000 to 681 knees in 2011. The average annual percentage increase in incidence was 33.2%. Females accounted for 83.2% of the patients who underwent primary total knee arthroplasty. In both males and females, the highest incidence was observed in the group aged 65 - 74 years. CONCLUSIONS: This study demonstrated a rapid increase in the incidence of primary total knee arthroplasty in our Chinese study population. The sex and age incidence of primary total knee arthroplasty in our study population differed from those reported in Western populations.

Double-bundle anterior cruciate ligament reconstruction using bone-patellar tendon-bone allograft: technique and 2- to 5-year follow-up.

BACKGROUND: Nonanatomic transtibial single-bundle anterior cruciate ligament reconstruction (SB-ACLR) with a bone-patellar tendon-bone (BPTB) allograft has been used for a long time and has shown the same satisfactory clinical results as an autograft; however, it has not been reported if a double-bundle ACLR (DB-ACLR) could be performed with a BPTB allograft and achieve even better results. HYPOTHESIS: The DB-ACLR with a BPTB allograft is technically feasible and will be superior to the SB technique in restoring better anterior and rotating stability. STUDY DESIGN: Cohort study; Level of evidence, 2. METHODS: The study was performed with 56 patients, and 52 (25 in the DB group and 27 in the SB group) of them were followed up at 2 to 5 years. With an irradiated deep-frozen BPTB allograft, a standard single-incision arthroscopic technique was used, and the graft was fixed with bioabsorbable interference screws on both the femoral and tibial sides. Outcome assessment at final follow-up included International Knee Documentation Committee (IKDC), Tegner, and Lysholm scores; side-to-side difference by conventional KT-2000 arthrometer; total anteroposterior (AP) laxity by the back-pushing KT-2000 arthrometer; pivot shift (0, +, ++); range of motion (ROM); and isokinetic muscle strength evaluation. RESULTS: Mean follow-up was 47.3 ± 11.5 and 58.2 ± 6.6 months for the DB group and SB group, respectively. A statistically significant difference in favor of the DB group was found with the total AP laxity at 30° (P < .05). The overall incidence of pivot shift in the DB group (4% ++) was significantly lower than that in the SB group (26%: 19% + and 7% ++; P = .029). No significant differences were found between the 2 groups in terms of IKDC score, Lysholm score, Tegner score, conventional KT-2000 arthrometer anterior laxity, ROM, and muscle strength. CONCLUSION: A DB-ACLR with a BPTB allograft is feasible and achieved more satisfactory results than the transtibial SB technique in terms of total AP stability and rotational stability in spite of no significant differences among other clinical parameters.

Computed tomographic measurement of gender differences in bowing of the sagittal femoral shaft in persons older than 50 years.

Surgeons do not give enough weight to the effects of bowing of the sagittal femoral shaft in total knee arthroplasty (TKA), which can result in damage to the cortex, fractures, or malalignment of the femoral component. To determine gender differences in bowing, we used spiral computed tomography to scan the femurs of 26 men and 47 women older than 50 years who required TKA. Skeletal extraction of the total sagittal femoral shaft from computed tomographic images was done by a matrix laboratory. The extracted curves were evenly divided into 3 sections. Comparison of the curvature on different sections of the same side of the femur showed that the distal third was significantly bowed. In addition, the curvature of the distal third was significantly larger in women than in men. Such morphological characteristics put forward new requirements in how intramedullary guide rods are used in TKA.

Second-look arthroscopic evaluation of the articular cartilage after primary single-bundle and double-bundle anterior cruciate ligament reconstructions.

BACKGROUND: Several reports have shown the progression of articular cartilage degeneration after anterior cruciate ligament (ACL) reconstruction. No report has been published about the cartilage comparing changes after single-bundle (SB) and double-bundle (DB) ACL reconstructions. The purpose of this study was to evaluate the articular cartilage changes after SB and DB ACL reconstructions by second-look arthroscopy. METHODS: Ninety-nine patients who received arthroscopic ACL reconstruction were retrospectively reviewed at an average of 14 months after reconstruction, 58 patients underwent SB ACL reconstruction and 41 patients underwent DB ACL reconstruction. Hamstring tendon autografts were used in all patients. Second-look arthroscopy was done in conjunction with the tibial staple fixation removal at least one year after the initial ACL reconstruction. Arthroscopic evaluation and grading of the articular cartilage degeneration for all patients were performed at the initial ACL reconstruction, and at the second-look arthroscopy. RESULTS: The average cartilage degeneration at the patellofemoral joint (PFJ) was found significantly worsened after both SB and DB ACL reconstructions. This worsening were not seen at medial tibiofemoral joint (TFJ) and lateral TFJ. Grade II cartilage damage was the most common. At second-look arthroscopy, the average patellar cartilage degeneration was 1.14 ± 0.14 (at first look 0.52 ± 0.11) for the SB group, and 1.22 ± 0.15 (at first look 0.56 ± 0.12) for the DB group. The average trochlear cartilage degeneration was 1.05 ± 0.16 (at fist look 0.10 ± 0.06) and 0.66 ± 0.17 (at fist look 0.17 ± 0.09), respectively. The average patellar cartilage degeneration showed no significant difference in both groups. However, the average trochlea cartilage degeneration in DB group was significantly less than in SB group. CONCLUSIONS: Patellofemoral cartilage degeneration continued to aggravate after ACL reconstruction. DB ACL reconstruction could significantly decrease the trochlea cartilage degeneration compared with SB ACL reconstruction.

[Anatomic and clinical study on 4-bone-tunnel double-bundle anterior cruciate ligament].

OBJECTIVE: To conduct a primary clinical analysis on 411 cases of arthroscopic 4 bone-tunnel double-bundle anterior cruciate ligament (ACL) reconstruction done by one operator on the basis of anatomic measurements of cadaver knees. METHODS: Twenty-two adult male Chinese cadaver knees of 25-45 years old were dissected. The sizes, distributions and positions of femoral and tibia footprints of anterior medial bundle (AMB) and posterior lateral bundle (PLB) of ACL and their fiber's orientations were measured and recorded. The anatomy and measurement results were used by one operator in 413 double-bundle ACL reconstruction knees of 411 cases with arthroscopic 4 bone-tunnel technique. Among them, 297 males and 114 females, there were 222 left knees and 191 right knees. The average age was 27.61 +/- 7.23 years old. RESULTS: The anatomy results showed the locations and sizes of AMB and PLB footprints in both femoral and tibia sides were different for different individuals. It was suggested to locate AMB femoral tunnel 7.95 +/- 1.40 mm inferior to 12:00 o'clock position on the posterior edge of the lateral wall of intercondylar fossa with 1 mm thick of the posterior wall of finished AMB femoral tunnel. With the knee flexed to 90 degrees, the PLB tunnel was 5.05 +/- 0.76 mm superior to the lower cartilage edge of the lateral wall of intercondylar fossa, 8.60 +/- 1.52 mm away from the anterior cartilage edge and 8.65 +/- 1.54 mm from the posterior edge. The anatomic orientations of tibia and femoral tunnels were also measured. The study results were used in arthroscopic double-bundle ACL reconstructions of 413 knees. In double-bundle ACL reconstruction operations, the grafts were used in the way from 2-strip double-bundle to 9-strip double-bundle. For most cases, Endo-Button was used for femoral fixation and bio-absorbable interference screw and staple were used for tibia fixation. For the patients adopting autologous semitendinosus and gracilis tendons (STG), the diameter of PLB bone tunnels was 5-6 mm in 95.9% cases, while that of AMB bone tunnel 5-7 mm in 72.4% cases. After a 28-month follow-up in 75 cases, the results showed that double-bundle ACL reconstruction could better reconstruct the stability of knees. CONCLUSION: In 4-bone-tunnel double-bundle arthroscopic ACL reconstruction, both bone tunnel positions and their orientations should be determined according to the anatomic measurement results. Since the PLB diameters of 95.9% cases were 5-6mm, considering the operative outcome of ACL revision, the double bundle ACL reconstruction technique was safe. A better knee stability could be reconstructed by this technique.

Comparative study on early period of recovery between minimally invasive surgery total knee arthroplasty and minimally invasive surgery-quadriceps sparing total knee arthroplasty in Chinese patients.

BACKGROUND: Different kinds of minimally invasive surgery (MIS) procedures have now been used in total knee arthroplasty (TKA). Compared with traditional TKA procedure with a long skin incision, clinical studies showed MIS procedures had some advantages. Quadriceps sparing (QS) procedures are the most minimally invasive MIS procedure until now. This study was aimed to find the insertion types for Chinese patients' vastus medialis and if the QS procedure had some advantages in patients' early recovery. METHODS: Between February 2006 and May 2007, 120 consecutive patients underwent unilateral primary TKA under general anesthesia, among whom 14 patients were lost to follow-up, the remaining 106 cases were enrolled in this study. Among the 106 cases there were 85 right knees, 21 left knees (15 men and 91 women, with a mean age of 65.1+/-7.4 years); osteoarthritis in 97 patients (91.5%) and rheumatoid arthritis in 9 patients (8.5%). MIS TKA was performed in 49 cases (MIS TKA group), while MIS-QS TKA in 57 cases (MIS-QS TKA group). During the operation, the type I, II and III insertions of the vastus medialis for all patients were recorded. Each knee was rated post-operatively according to the Hospital of Special Surgery (HSS) scoring system. Clinical follow-up was undertaken at 1 week, 2, 6, 12 and 24 weeks. Operating time and complications were recorded. RESULTS: There was no statistically significant difference between the two groups for gender distribution, age, left or right knee incidence, pre-operative diagnosis, incidence of varus or valgus deformity. Of the 106 cases there was 1 (0.9%) case with a type I insertion of the vastus medialis, 4 (3.8%) cases with type II insertions, 101 (95.3%) cases with type III insertions. The HSS scoring was significantly different between the MIS-QS TKA group and MIS TKA group within the first two weeks post operation. From 2 weeks later to 24 weeks, no significant difference was found. The average operating time was (53.3+/-12.4) minutes in the MIS TKA group and (64.1+/-15.1) minutes in the MIS-QS TKA group (P<0.001). In the MIS-QS TKA group, 1 patient had delayed healing of the partial skin incision (1.8%). No other complications were found in either group. CONCLUSIONS: Although most of the Chinese patients had type III insertions of the vastus medialis, the MIS-QS TKA procedure showed less injury to the quadriceps than the standard MIS TKA and this could contribute to the earlier recovery of the patients. But a shorter skin incision and more tension on the skin may also lead to more skin complications.

Rat adipose-derived stromal cells expressing BMP4 induce ectopic bone formation in vitro and in vivo.

AIM: Bone morphogenetic protein 4 (BMP4) is one of the main local contributing factors in callus formation in the early phase of fracture healing. Adipose-derived stromal cells (ADSC) are multipotent cells. The present study was conducted to investigate the osteogenic potential of ADSC when exposed to adenovirus containing BMP4 cDNA (Ad-BMP4). METHODS: ADSC were harvested from Sprague-Dawley rats. After exposure to Ad-BMP4, ADSC were assessed by alkaline phosphatase activity (ALP) assay, RT-PCR and von Kossa staining. BMP4 expression was assessed by RT-PCR, immunofluorescence and Western blot analysis. ADSC transduced with Ad-BMP4 were directly injected into the hind limb muscles of athymic mice. ADSC Ad-EGFP(enhanced green fluorescence protein) served as controls. All animals were examined by X-ray film and histological analysis. RESULTS: The expression of BMP4 was confirmed at both mRNA and protein levels. The expression of the osteoblastic gene, ALP activity and von Kossa staining confirmed that ADSC transduced with Ad-BMP4 underwent rapid and marked osteoblast differentiation, whereas ADSC transduced with Ad-EGFP and cells left alone displayed no osteogenic differentiation. X-ray and histological examination confirmed new bone formation in athymic mice transplanted with ADSC transduced with Ad-BMP4. CONCLUSION: Our data demonstrated successful osteogenic differentiation of ADSC transduced with Ad-BMP4 in vitro and in vivo. ADSC may be an ideal source of mesenchyme lineage stem cells for gene therapy and tissue engineering.