Is mid-sulcus line a predictive guide for tibial mechanical axis during total knee arthroplasty?

BACKGROUND: Achieving appropriate alignment of components in total knee arthroplasty (TKA) is essential for optimal functional outcomes as well as implant longevity. Performing TKA in the absence of a computer-assisted navigation system (CANS) mandates the use of accurate anatomical landmarks for achieving appropriate alignment. In this study, we have evaluated the reliability of 'mid-sulcus line' as an anatomical landmark to guide tibial resection, with the intra-operative help of CANS. METHOD: A total of 322 patients undergoing primary TKA (excluding previously operated limbs and limbs with extra-articular deformities of tibia or femur) using CANS were included in the study. After resecting ACL, the mid-suclus line was drawn with a cautery tip. We hypothesized that if tibial cut was made perpendicular to the mid-sulcus line, coronal alignment of the tibial component would be along the neutral mechanical axis. This was evaluated intra-operatively with the help of CANS. RESULTS: Of 322 knees, identification of the 'mid-sulcus line' was possible in 312 knees. The mean angle between the tibial alignment defined by mid-sulcus line and the neutral mechanical axis was found to be 0.45° (range, 0-1.5°) (P < 0.05). In all of the 312 knees, the tibial alignment defined by mid-sulcus line was found to be within 3° of the neutral mechanical axis (confidence interval: 0.410°, 0.491°). CONCLUSION: Mid-sulcus line can be used as an additional anatomical landmark to guide the tibial resection and thereby achieve appropriate coronal alignment in primary TKAs without any extra-articular deformity.

Are soft tissue releases sufficient to correct moderate to severe flexion contractures during total knee replacement? Role of hamstring tenotomy and horizontal capsular release.

BACKGROUND: Performing total knee arthroplasty (TKA) in arthritic knees with persistent flexion deformities is a challenging task because secondary tightening of surrounding soft tissues makes it difficult to achieve appropriate ligament balancing. In this study, we shared our algorithm for correction of flexion contractures of moderate to severe grade while performing TKA as well as their outcomes with 1 year of follow up. METHODS: Forty-three patients (61 knees) having knee arthritis with moderate to severe flexion contractures (Lombardi classification) were included in the study. We followed a stepwise algorithm of soft tissue releases for correction of flexion contracture, which included: removal of posterior osteophytes, release of posterior capsule, gastrocnemius release, horizontal capsular release, and hamstring tenotomy. Patients were followed up at 15 days, 6 weeks, 3 months and 1 year, and assessed clinically for residual flexion deformity (FFD), range of motion (ROM), New Knee Society (New KSS) score and Hospital for Special Surgery (HSS) score. RESULTS: Pre-operative mean FFD 29.07 ± 18.04 standard deviation (SD) was corrected to 0.77 ± 2.93 SD at 1 year follow up. Pre-operative mean ROM 71.37 ± 22.18 increased to 107.7 ± 10.38 at 1 year follow up. There was statistically significant improvement in mean New KSS score and reduction in number of cases with poor HSS score at 1 year follow up. CONCLUSIONS: Moderate flexion contractures can be corrected with soft tissue releases without distal femoral over-resection. In severe deformities, horizontal release of posterior capsule and hamstring tenotomy are crucial, and residual contractures of up to 20° can be well corrected by postoperative physiotherapy and extension bracing.

Minimally invasive plate osteosynthesis using a locking compression plate for distal femoral fractures.

PURPOSE: To evaluate treatment outcomes of minimally invasive plate osteosynthesis (MIPO) for distal femoral fractures in 31 patients. METHODS: 22 male and 9 female consecutive patients aged 21 to 65 (mean, 42) years underwent minimally invasive plate osteosynthesis using a locking compression plate (LCP) for distal femoral fractures. The causes of injury were vehicular accidents (n=24), falls (n=6), and assault (n=1). According to the AO classification, the fractures were classified as types A1 (n=10), A2 (n=7), and A3 (n=14). Most fractures were closed; 3 were Gustilo type-II fractures. Clinical and functional outcomes were assessed using the Knee Society Scores. RESULTS: The mean operating time was 70 (range, 60-100) minutes. The mean length of hospital stay was 9 (6-14) days. The mean time to union was 3.7 (range, 2.8-4.6) months. The mean follow-up period was 18 (14-26) months. At the one-year follow-up, 29 of the patients had good or excellent outcomes. No patient had angular or rotational deformity of >10º. One osteoporotic woman with a type-A1 fracture had implant failure at 10 weeks and underwent revision surgery. Another patient with a type-A1 fracture had persistent pain on the lateral aspect of the distal thigh and underwent implant removal at 22 months. No patient developed deep infection, malunion or nonunion. CONCLUSION: MIPO using a LCP achieves favourable biological fixation for distal femoral fractures with few complications. Bone grafting is not needed even in cases of metaphyseal comminution. Proper patient selection and preoperative planning are essential to prevent complications.