Changes in hamstring strength after anterior cruciate ligament reconstruction with hamstring autograft and posterior cruciate ligament reconstruction with tibialis allograft

Methods@#Isokinetic strengths of the quadriceps and hamstring muscles and endurances were compared between a group of 20 patients undergoing PCLR using a tibialis anterior allograft and a 1:2 matched control group of 40 patients undergoing ACLR using a hamstring autograft at 2 years after the operations. Clinical results were also compared using stability tests and the Lysholm and the International Knee Documentation Committee scores. @*Results@#At 2 years after the operations, the torque deficit of the hamstring muscle in the involved leg compared to the uninvolved leg at both 60°/s and 120°/s was greater in the PCLR group than in the ACLR group (60°/s, 21.8 ± 14.0% versus 1.9 ± 23.9%, P = 0.0171; 120°/s, 15.3 ± 13.7% versus −0.7 ± 17.4%, P = 0.012, respectively). The peak torque of the hamstring muscle at 120°/s was significantly lower in the involved leg than in the uninvolved leg only in the PCLR group (71.3 ± 31.9 N·m versus 81.9 ± 27.8 N·m, P = 0.005). There was no significant difference in the clinical results between the groups except for a side-to-side difference in the tibial translation on Telos stress radiographs. @*Conclusion@#The strength of the hamstring of the PCLR leg with allograft was significantly weaker than that of the unoperated leg after 2 years, whereas that of the ACLR leg with hamstring autograft maintained a similar level of strength compared to that of the uninvolved leg.Level of evidence: Level III, case–control study.

Disparity between Preoperative Target Correction Amount and Postoperative Correction Amount in Open Wedge High Tibial Osteotomy

PURPOSE: The purpose of this study was to evaluate the disparity between the preoperative target correction amount and the postoperative correction amount in open wedge high tibial osteotomy (OWHTO) in patients divided according to the planned osteotomy gap. MATERIALS AND METHODS: Seventy-two patients were divided into two groups (group 1 with the planned opening gap lager than the mean opening gap length of total patients and group 2 with a smaller opening gap). The opening gap was determined according to the target weight bearing line (WBL) ratio on the preoperative whole leg radiograph. Absolute and relative values of the disparity between the target and postoperative WBL ratios were compared between groups in order to clarify whether the disparity was deviated toward over- or under-correction. RESULTS: The absolute value of disparity between the target and postoperative WBL ratios in group 1 was significantly larger than that in group 2 (6.01%±5.68% vs. 3.32%±3.38%; p=0.02). However, there was no statistically significant difference in relative values between groups (p=0.54). CONCLUSIONS: The postoperative WBL ratio after OWHTO was different from the preoperative target WBL ratio if the planned osteotomy gap was large. This mismatch was not deviated toward one side, either over- or under-correction.

Preoperative Varus-Valgus Stress Angle Difference Is Valuable for Predicting the Extent of Medial Release in Varus Deformity during Total Knee Arthroplasty

PURPOSE: The purpose of this study was to compare the predictive value of the valgus stress angle (SA), varus SA and varus-valgus SA difference (VVD) in predicting the degree of medial release in varus deformity during total knee arthroplasty (TKA). MATERIALS AND METHODS: One hundred eight TKAs (78 patients), which were performed in primary osteoarthritis with varus knee deformity, were retrospectively classified into three groups according to the degree of medial release (group A, mild release; group B, moderate release; and group C, severe release). Medical charts were reviewed, and long weight bearing standing anteroposterior radiographs and varus-valgus stress radiographs were evaluated. RESULTS: The valgus SA was significantly different between group A and B and between group A and C. However, it was not significantly different between group B and C. The varus SA was significantly different between group B and C and between group A and C. However, it was not significantly different between group A and B. The VVD was significantly different in all intergroup comparisons. CONCLUSIONS: Evaluation of the VVD is more valuable in predicting the degree of medial release in TKA performed in varus knee deformity than evaluation of the simple valgus and varus SA.

Does Coronal Knee and Ankle Alignment Affect Recurrence of the Varus Deformity after High Tibial Osteotomy?

PURPOSE: The purpose of this study was to evaluate changes in the coronal alignment of the knee and ankle joints after open wedge high tibial osteotomy (OWHTO) to determine factors related to the recurrence (R) of the varus deformity by serial analysis. MATERIALS AND METHODS: Sixty-four OWHTOs were enrolled in this study. The weight bearing line (WBL) ratio, joint line convergence angle (JLCA), knee joint inclination, mechanical axis-tibial plateau angle, talar inclination (TI), and distal tibia articular angle (DTAA) were serially assessed. Serial correlation analysis between all parameters was performed. Patients were divided into R group and no recurrence (NR) group according to the WBL ratio (55%) at postoperative one year. RESULTS: The preoperative WBL ratio showed significantly negative correlation with serial changes of JLCA, TI, and DTAA (p < 0.05). The JLCA, TI, and DTAA as well as WBL ratio showed a significantly larger degree of varus alignment in the R group than in NR group at postoperative 6 weeks and 1 year after OWHTO (p < 0.05). CONCLUSIONS: Sufficient correction of the WBL and restoration of the JLCA during OWHTO are essential to prevention of the R of varus deformity after the surgery because they are the only modifiable factors during surgery. LEVEL OF EVIDENCE: IV, Case series