Accelerometer-based portable navigation, a faster guide compared to computer-assisted navigation in bilateral total knee arthroplasty-a randomized controlled study.

PURPOSE: There are limited studies in the literature comparing the alignment accuracy of  the large console, imageless, computer-assisted navigation (CAN) and portable, hand-held, accelerometer-based navigation (ABN) in total knee arthroplasty (TKA).  This study was aimed to compare the operative time, blood loss, radiological, clinical and functional outcomes between CAN- and ABN-guided bilateral TKA. METHODS: From Jan 2016 to Dec 2017, 50 patients who underwent bilateral TKA were randomized to undergo either CAN-guided or ABN-guided TKA. Tourniquet time and blood loss were recorded, and intra-op complications were noted. Post-op radiological outcomes at 2 weeks were compared between the groups. The clinical and functional outcomes using the American Knee Society Scores (KSS) and Oxford Knee Score (OKS) were recorded pre-operatively and post-operatively at 3, 6, 12 months and at the end of the study with a minimum follow-up of 48 months. RESULTS: Both groups were well-matched in terms of patient demographic parameters. The mean surgical time per knee was significantly lower in the ABN group (54.5 ± 5.6 min) compared to the CAN group (61.7 ± 13.7 min; p < 0.01). Mean blood loss per knee in the ABN group was 592.1 ± 245.3 mL compared to 682.8 ± 322.0 in the CAN group (p = 0.11). In the ABN group, the mean post-op mechanical axis was 1.2 ± 3.2° (vs 1.5 ± 2.2° in the CAN group, p 0.6), the frontal femoral angle was 88.8 ± 2.3° (vs 88.8 ± 1.8° in the CAN group, p 1.0) and frontal tibial angle was 90.1 ± 1.6° (vs 89.7 ± 1.1° in the CAN group, p 0.14). At 48 month follow-up, the mean functional KSS in the ABN group was 89.0 ± 5.7 (vs 88.1 ± 4.5 in the CAN group, p 0.37) and the mean OKS was 40.5 ± 2.8 (vs 39.6 ± 3.2 in the CAN group, p 0.12). CONCLUSION: Portable, hand-held ABN offers alignment accuracy and functional outcomes in TKA similar to that with CAN, with a reduced duration of surgery. There was no advantage of either of the techniques in terms of clinical or functional outcomes at 48 month follow-up. LEVEL OF EVIDENCE 1.

Thumb Opposition Recovery Following Surgery for Severe Carpal Tunnel Syndrome: A Clinical, Radiological, and Electrophysiological Pilot Study.

PURPOSE: To objectively assess recovery of thumb opposition in patients with carpal tunnel syndrome (CTS) after open carpal tunnel release and to evaluate electrophysiological and magnetic resonance (MR) neurography findings as predictors of thumb opposition recovery. METHODS: A total of 22 patients with severe CTS and thenar atrophy were included in this study. A detailed clinical, electrophysiological, and MR neurography evaluation was done both before and after surgery at 6 months to assess thumb opposition recovery. RESULTS: The median duration of symptoms was 12 months (interquartile range, 12-20 months). The compound muscle action potential of the abductor pollisis brevis (CMAP-APB) also showed statistically significant improvement of 0.5 + 0.2 mV after surgery. Tip-tip pulp pinch strength increased from 1.2 ± 0.4 to 2.0 ± 0.4 kg at 6-month follow-up, lateral pulp pinch strength increased from 1.9 ± 0.6 to 2.8 ± 0.9 kg at 6-month follow-up, and 3-point pulp pinch also improved from 1.9 ± 0.5 to 2.8 ± 0.9 at final follow-up. On MR neurogram, the proportion of patients with abnormal median nerve morphology decreased from 81.8% to 68.2%, abnormal thenar branch morphology decreased from 63.6% to 36.4% and denervation edema deceased from 59.1% to 13.6%. CONCLUSIONS: Patients suffering from severe CTS with thenar atrophy and detectable CMAP-APB showed promising improvement following open carpal tunnel release. TYPE OF STUDY/LEVEL OF EVIDENCE: Prognostic IV.

Proximal femoral nails compared with reverse distal femoral locking plates in intertrochanteric fractures with a compromised lateral wall; a randomised controlled trial.

PURPOSE: There is no consensus about the best option of internal fixation for unstable intertrochanteric fractures. The aim of the present study was to compare proximal femoral nail (PFN) with contralateral reverse distal femoral locking compression plate (reverse-DFLCP) in the management of unstable intertrochanteric fractures with compromised lateral wall. METHOD: In a randomized controlled study, from November 2011 to October 2012, 40 patients with unstable intertrochanteric fractures with compromised lateral wall (AO 31A 2.2 to 3.3) had osteosynthesis by PFN (n = 20) or reverse-DFLCP (n = 20). Intra-operative variables compared were duration of surgery, blood loss during surgery, fluoroscopy time and surgeons perception of the surgery. Patients were followed up clinically for a minimum of one year. Functional outcome was assessed by Parker Palmer mobility score (PPMS), Harris hip score (HHS), and Short Form-12. Failure was defined as any condition which would necessitate revision surgery with change of implant. RESULTS: Duration of surgery (p = 0.022), blood loss during surgery (p = 0.008) and fluoroscopy time (p = 0.0001) were significantly less in the PFN group than in the reverse-DFLCP group. No significant difference was found in type of reduction, difficulty in reduction and surgeon's perception of surgery. The PFN group had better functional outcome than the reverse-DFLCP group. HHS for the PFN group was 81.53 ± 13.21 and for the reverse-DFLCP group it was 68.43 ± 14.36 (p = 0.018). SF-12 physical (p = 0.002) and mental component (p = 0.007) scores in the PFN group was significantly better than in the reverse-DFLCP group. There was one failure in the PFN group as compared to six in the reverse-DFLCP group (p = 0.036). CONCLUSION: Due to favourable intra-operative variables, better functional outcome and lower failure rates, we conclude that PFN is a better implant than reverse-DFLCP for intertrochanteric fractures with compromised lateral wall.

Direct Anterior Approach in Total Hip Arthroplasty: A Single Center Experience.

Purpose: The direct anterior approach (DAA) for conducting total hip arthroplasty (THA) is gaining popularity worldwide. However, careful selection of patients and surgeon experience are important. Although promising outcomes have been reported in international studies, research on DAA in Southern and Southeast Asia has been limited. Materials and Methods: This prospective study included 157 patients who underwent THA using the DAA between January 2019 and June 2022. The patients were divided into three groups for the comparison. Data on preoperative, intraoperative, and postoperative variables were acquired. Improvement of the surgeon's performance to use of a DAA approach was examined using the CUSUM (cumulative summation method). Results: The mean age of the patients was 43.9 years. Differences in intraoperative variables and complications were observed among the three groups, and improved outcomes were reported in later cases. Functional outcomes showed significant improvement, and no differences were observed between groups. The results of learning curve analysis indicated a shift towards consistent success after the 82nd case, reaching an acceptable rate of failure by the 118th case. Conclusion: The findings of this study suggest that DAA can offer benefits but there is a learning curve. Complications were initially high but began decreasing after approximately 80 cases. Careful selection of patients is critical, particularly in the effort to minimize being presented with a challenging case. This study provides insights that may be helpful to surgeons when considering DAA; however, further study is warranted.

Sciatic nerve palsy after direct anterior approach for total hip replacement.

SummarySciatic nerve injury after total hip replacement is rare with a reported incidence of about 0.09%-3.7%. The most commonly reported causes include traction on the nerve during reduction, compression of the nerve from subfascial haematoma, significant leg lengthening, improper retractor placement, thermal burns from cautery and extraneous cement. We present a case of complete sciatic nerve palsy in a patient operated on using direct anterior approach (DAA). To date, there are no reports describing sciatic nerve palsy secondary to haematoma immediately after primary arthroplasty through the DAA. We performed an MRI of lumbosacral spine with both hips, which revealed a haematoma. Consequently, we promptly took the patient to the operation theatre for re-exploration. Using the same approach, we dislocated the hip and removed the clots. By the end of 2 weeks, the patient was able to dorsiflex the ankle and had fully recovered from sciatic nerve palsy.

Risk Factors and Outcomes Associated with Intraoperative Fractures during Short-Stem Total Hip Arthroplasty for Osteonecrosis of the Femoral Head.

BACKGROUND: Young age in osteonecrosis of the femoral head (ONFH) demands bone-preserving, short-stem arthroplasty. Several designs including neck-preserving stems and neck-resecting, shortened, standard stems are classified as short stems. There is a paucity of literature investigating risk factors and outcomes of intraoperative complications of neck preserving, short-stem arthroplasty in ONFH. METHODS: A total of 107 hips operated with METHA short-stem arthroplasty for ONFH were retrospectively evaluated. The mean age of patients was 43.7 years (range, 27-60 years). Nine patients had an intraoperative fracture. Seven hips received prophylactic cerclage wiring for poor bone quality. Patients were invited for clinical and radiological evaluation at the latest follow-up. RESULTS: The mean follow-up of patients was 47.2 months. Significant association with intraoperative fractures and the need for prophylactic cerclage wiring were found in steroids-, alcohol-, and chronic renal failure-induced ONFH. However, patient sex, body mass index, traumatic/idiopathic ONFH, previous implant in situ, prosthesis size, and single-sitting bilateral total hip replacement (THA) were not the risk factors. All hips showed signs of osteointegration at final follow-up. No revision was done during the study period for any cause. CONCLUSIONS: METHA short-stem THA offers excellent functional and radiological outcomes in ONFH. However, precaution must be exercised in patients with steroids-, alcohol-, and renal disorders-induced ONFN due to poor bone quality and higher chances of intraoperative fractures. Also, additional measures such as the use of a high-speed burr and prophylactic cerclage wiring in ONFH may allow predictable and safe use of short stems.

Functional and radiological outcomes following plating for displaced fractures of patella: A pilot study.

INTRODUCTION: Patellar fractures constitute almost 1% of total skeletal injuries. Existing common operative methods include the use of different types of Tension band wiring techniques like cannulated screws and K-wires. The Patellar plating construct is a relatively newer operative method for patellar fracture fixation with promising outcomes with fewer complications. METHOD: We conducted a pilot prospective study at our Apex Trauma center in twenty patients aged 18-65years with displaced patellar fractures, AO type A2, A3, B2, B3, C1, C2, C3. Fractures were fixed with low profile patellar plates (1.8 mm). Radiological and functional follow-up was done using X-rays, CT scans and BKS scoring (Bostman-Knee-Scale), Knee Society Score(KSS), and Tegner Lysholm knee scores respectively for two years. RESULT: Mean functional outcome scores at 6 weeks, 3 months, 6 months and 2 years was 25.5, 28.3, 29.05 and 29.9 for BKS; 64.62, 84.12, 90.6, and 97.5 for KSS; 73.75, 89.7,94.8, and 99.3 for Tegner Lysholm knee score respectively. Radiological union, confirmed by CT scan, was observed in all patients at 3 months. Two patients had superficial surgical site infection (SSI) at 2 weeks. Implant impingement was also found in 2 patients at 3 months. None of the patients had a failure of fixation at the end of the study. CONCLUSION: Patients with low profile patellar plate constructs have favorable clinical and radiological outcomes with minimal non-specific complications.

Accelerometer-based, hand-held navigation for improved knee alignment in total knee arthroplasty: An observational study.

BACKGROUND: Malalignment in total knee arthroplasty has been associated with poor implant longevity and clinical outcomes. The aim of this study was to investigate the accuracy of accelerometer-based navigation in restoring the mechanical axis. METHODS: 106 primary total knee arthroplasties performed during February 2016 to September 2017 at a tertiary care centre in India were enrolled in this observational study. We noted the intra-op tourniquet time. Two separate blinded observers measured the preoperative mechanical axis and the post operative radiological results (mechanical axis, coronal and sagittal alignment of femoral and tibial components) and the mean value was taken as final data. Interclass correlation was done to look for variability between the two observers. RESULTS: The mean pre operative mechanical axis was 13.74 ± 10.44. The mean tourniquet time was 53.14 ± 7.42 min 91.5% (96/106) knees were within ±3° of neutral mechanical axis with a mean of 1.00° ± 2.68°. The femoral and tibial components with coronal alignment within ±3° perpendicular to the mechanical axis were 93.39% (99/106) and 89.62% (95/106) respectively. In the sagittal plane 89.62% of the femoral components and 87.73% of the tibial components were within ±3° perpendicular to the axis of tibia. CONCLUSION: The Accelerometer based portable navigation system effectively reduces the coronal and sagittal alignment outliers in total knee arthroplasty and has no role in rotational alignment of components.

Navigated Unicompartmental Knee Arthroplasty: A Different Perspective.

BACKGROUD: Anteromedial osteoarthritis is a recognized indication for unicompartmental knee arthroplasty (UKA). Favorable postoperative outcomes largely depend on proper patient selection, correct implant positioning, and limb alignment. Computer navigation has a proven value over conventional systems in reducing mechanical errors in total knee arthroplasty (TKA). However, the lack of strong evidence impedes the universal use of computer navigation technology in UKA. Therefore, this study was proposed to investigate the accuracy of component positioning and limb alignment in computer navigated UKA and to observe the role of navigation in proper patient selection. METHODS: A total of 50 knees (38 patients) underwent computer navigated UKA between 2016 and 2018. All operations were performed by the senior surgeon using the same navigation system and implant type. The navigation system was used as a tool to aid patient selection: knees with preoperative residual varus > 5° on valgus stress and hyperextension > 10° were switched to navigated TKA. We measured the accuracy of component placement in sagittal and coronal planes on postoperative radiographs. Functional outcomes were also evaluated at the final follow-up (a minimum of 16 months). RESULTS: Nine patients had tibia vara and 14 patients had preoperative hyperextension deformity. We observed coronal outliers for the tibial component in 12% knees and for the femoral component in 10% knees. We also observed sagittal outliers for the tibial component in 14% knees and for the femoral component in 6% knees. There was a significant improvement in the functional score at the final follow-up. On multiple linear regression, no difference was found in functional scores of knees with or without tibia vara (p = 0.16) and with or without hyperextension (p = 0.25). CONCLUSIONS: Our study further validates the role of computer navigation in desirable implant positioning and limb alignment. We encourage use of computer-assisted navigation as a tool for patient selection, as it allows intraoperative dynamic goniometry and provides real-time kinematic behavior of the knee to obviate pitfalls such as significant residual varus angulation and hyperextension that predispose early failure of UKA.

Current updates in image-guided musculoskeletal interventions.

Image-guided musculoskeletal interventions are frequently done in clinical practice. Even then, the literature regarding their effectiveness is relatively scarce. Image guidance adds value over the conventional landmark-based approach and should be preferred. We hereby try to list the commonly performed procedures along with the current practice guidelines regarding their clinical indications and periprocedural care.

Habitual patellar dislocation in children: Results of surgical treatment by modified four in one technique.

BACKGROUND: Habitual patellar dislocation is a rare condition affecting children. The growth plates are open in children and any surgical intervention should take that in to consideration. We are describing a modified four in one technique for habitual patellar dislocation, which is a soft tissue procedure without the use of any implant. METHOD: In this study we included 6 children (4 females and 2 males) with open growth plates, which were diagnosed with habitual patellar dislocation. The average age of the patients were 9.6 years (range 5-13 years). Our technique included lateral retinaculum release, vastus medialis obliques (VMO) advancement, partial patellar tendon transposition and reconstruction of medial patellofemoral ligament (MPFL). Patients were evaluated with Kujala scoring pre and post operatively. The average follow up period was 12 months (range 7-24 months). RESULTS: There were no recurrence of patellar instability in any of the cases. The mean Kujala score was 48 before surgery and it improved to 95 after 12 months of average follow-up after surgery. CONCLUSION: We conclude that our method of treatment of habitual patellar dislocation by using modified four in one technique in children with open physis reproduced excellent functional outcome. It is simple, cheap and does not require any image guidance. THERAPEUTIC STUDY: Level of evidence IV.