Positional relationship between the Achilles tendon and sural nerve on ultrasound.

PURPOSE: This study sought to clarify the positional relationship between the Achilles tendon and sural nerve using ultrasound. METHODS: We studied 176 legs in 88 healthy volunteers. The positional relationship between the Achilles tendon and sural nerve at heights of 2, 4, 6, 8, 10, and 12 cm proximal from the calcaneus' proximal margin was investigated by distance and depth. Setting the X-axis (left/right) as the horizontal axis and Y-axis (depth) as the vertical axis against ultrasound images, we investigated the distance between the lateral margin of the Achilles tendon to the midpoint of the sural nerve on the X-axis. The Y-axis was split into four zones: the part behind the center of the Achilles tendon (AS), the part in front of the center of the Achilles tendon (AD), the part behind the Achilles tendon (S), and the part in front (D). We investigated the zones through which the sural nerve passed. We also studied any significant differences between the sexes and left/right legs. RESULTS: The mean distance on the X-axis was closest at 6 cm, with 1.1 ± 5.0 mm between them. The sural nerve's position on the Y-axis was such that at positions more proximal than 8 cm, the sural nerve ran through zone S in most legs and moved to zone AS through heights 2-6 cm. No parameters showed significant differences between the sexes or left/right legs. CONCLUSION: We presented the positional relationship between the Achilles tendon and sural nerve and suggested some measures to prevent nerve injury during surgery.

Treatment of a sacral fracture associated with an intrasacral meningocele: A case report.

We report a case of sacral fracture complicated by an intrasacral meningocele in a 37-year-old male. The patient had a left sacral fracture with bilateral fractures of the superior and inferior pubic rami. The sacrum was fixed with a posterior plate and both superior pubic rami were fixed with an intramedullary screw. However, computed tomography myelogram and magnetic resonance imaging showed the intrasacral meningocele with the leakage of the cerebrospinal fluid into the buttocks and developed delayed union. Reoperation utilizing a strong anterior and posterior internal fixation combined with posterior bone grafting was undertaken and bone union was obtained.

Age does not affect the clinical and radiological outcomes after open-wedge high tibial osteotomy.

PURPOSE: Open-wedge high tibial osteotomy (OWHTO) is a well-established procedure in the management of medial compartment osteoarthritis and osteonecrosis of the medial femoral condyle. Several studies have evaluated factors that negatively influence outcomes. However, few reports have investigated the effect of age on HTO outcome. We evaluated the influence of the age on the outcome after HTO. METHODS: The TomoFix® plate was used to perform 60 consecutive OWHTOs. Twenty-six knees in 23 patients >65 years old (mean age at surgery 68.7 ± 2.9 years; range 65-75 years, group A) were compared with 34 knees in 27 patients <65 years old (mean age at surgery 56.2 ± 7.5 years; range 38-64 years, group B) with respect to the clinical and radiological outcomes after HTO. The clinical evaluation included the Japanese Orthopedic Association Knee Score (JOA score), Oxford Knee Score (OKS) and complications after surgery. RESULTS: There were no statistical differences in the background factors between the two groups. Postoperatively, the mean JOA score showed a significant improvement in both groups. The mean OKS after surgery was 41.6 ± 5.9 in group A and 41.4 ± 5.9 in group B. There were no statistical differences in the postoperative knee alignment and clinical outcomes between the two groups. CONCLUSION: OWHTO using the rigid long plate was an effective procedure independent of patient's age. The results showed that age did not influence the clinical and radiological outcomes after OWHTO.

A refined definition improves the measurement reliability of the tip-apex distance.

BACKGROUND: Tip-apex distance (TAD) is reported as a good predictor for cut-outs of lag screws and spiral blades in the treatment of intertrochanteric fractures, and surgeons are advised to strive for TAD within 20 mm. However, the femoral neck axis and the position of the lower limb in the lateral radiograph are not clearly defined and can lead to measurement errors. We propose a refined TAD by defining these factors. The objective of this study was to analyze the reliability of this refined TAD. METHODS: The radiographs of 130 prospective cases with unstable trochanteric fractures were used for the analysis of the refined TAD. The refined TAD was independently measured by 2 raters with clinical experience of more than 10 years (rater 1, 2) and 2 raters with much less clinical experience (rater 3, 4) after they received a training about the new measurement method. Intraclass correlation coefficient (ICC [2,4]) was calculated to assess the interrater reliability. RESULTS: The mean refined TADs were 18.2:18.4:18.2:18.2 mm for rater 1:2:3:4. There was a strong correlation among all four raters (ICC 0.998, (95% CI: 0.998, 0.999). CONCLUSIONS: Regardless of the clinical experience of raters, the refined TAD is a reliable tool and can be used to develop new TAD recommendations for predicting failure of fixation. Future studies with larger samples are needed to evaluate the predictive value of the refined TAD.

Geriatric tibial plateau fractures: Clinical features and surgical outcomes.

BACKGROUND: Operative treatment of geriatric tibial plateau fractures is challenging and controversial. There are few studies focusing on the clinical features and operative outcomes of tibial plateau fractures in the elderly. Hence, this study aimed to investigate the clinical features and operative results of these fractures. METHODS: Thirty-three displaced tibial plateau fractures in patients >65 years old (mean age: 72.1 years, range: 65-94 years) were treated operatively. We investigated the mechanisms of injury, fracture types according to the Schatzker classification, incidences of soft tissue injury, and postoperative complications. Clinical and radiographic data were analyzed in 23 patients at the last follow-up. The mean follow-up period was 4.0 years (range: 1-13 years). Twenty-one patients were treated with open reduction and internal fixation and evaluated using the Rasmussen clinical and radiologic scores. Two patients with advanced osteoarthritis were treated primarily with total knee arthroplasty and assessed using the Japanese Orthopaedic Association score for the knee osteoarthritis. RESULTS: Twenty-four patients (72.7%) were injured by low-energy trauma such as a simple fall. Four patients had compartment syndrome and required fasciotomies. Rasmussen clinical and radiologic scores were satisfactory in 85.7% and 81.0% of patients, respectively. Two patients treated primarily with total knee arthroplasty showed no radiologic abnormality, and their Japanese Orthopaedic Association scores were both 70 points. CONCLUSIONS: Geriatric tibial plateau fractures, although mostly due to low-energy trauma, were often accompanied with severe comminution and compartment syndrome. Postoperative results of open reduction and internal fixation for this population were relatively good. Therefore, primary total knee arthroplasty should only be considered for well-selected patients.

Do design adaptations of a trochanteric nail make sense for Asian patients? Results of a multicenter study of the PFNA-II in Japan.

PURPOSE: Asian patients with osteoporosis suffer from an increased incidence of hip fracture and a potentially increased risk of fixation failure due to anatomical differences compared to Caucasians. To cope with these differences, an Asian size- and geometry-adapted Proximal Femoral Nail Antirotation (PFNA-II) was developed. The objective of this prospective multicenter study was to assess the risk of fracture fixation complications (FFCs), the occurrence of mismatch and the quality of life status of patients treated with the PFNA-II. PATIENTS AND METHODS: 176 Japanese patients with an isolated, unstable, closed trochanteric fracture were treated with the PFNA-II. Patients were prospectively screened for anticipated complications and classified accordingly; complications were centrally reviewed by a complication review board to avoid bias by the treating surgeon, and categorized using a standardized reporting system. Outcome measurements included the occurrence and evaluation of FFCs, the radiological assessment of mismatch and quality of life measured with the EQ-5D score. RESULTS: 3 Intraoperative and 15 postoperative complications were found in 16/176 patients. The risk of sustaining any intraoperative or postoperative FFC was 1.7% (3/176; 95% CI: 0.35-4.9) and 8% (14/176; 95% CI: 4.4-13), respectively. The most likely cause for FFCs was the "bone/fracture" factor (9/14 patients). Radiologically detectable contact of the implant with the inner cortex ("mismatch") was reported for 17/173 patients (10%). CONCLUSIONS: The reported complication risks and mismatches are reasonable for this patient cohort. The geometry- and size-adapted PFNA-II is relatively safe but requires standardized assessment in a larger target cohort.

Polyneuropathy caused by cobalt-chromium metallosis after total hip replacement.

Although metal intoxication after arthroplasty causes various symptoms, polyneuropathy has never been the focus of clinical investigation. We report the case of a 56-year-old woman with metal neuropathy. She had metallosis after hip arthroplasty with a cobalt-chromium alloy prosthesis. She developed progressive sensory disturbance, hearing loss, and hypothyroidism. Sural nerve biopsy indicated axonopathy. After exchange arthroplasty, blood levels of cobalt and chromium decreased, and her symptoms improved. Cobalt or chromium can cause axonopathy.

A mechanical analysis of femoral resurfacing implantation for osteonecrosis of the femoral head.

Hip resurfacing is becoming a popular procedure for treating osteonecrosis of the femoral head. However, the biomechanical changes that occur after femoral resurfacing have not been fully investigated with respect to the individual extent of the necrosis. In this study, we evaluated biomechanical changes at various extents of necrosis and implant alignments using the finite element analysis method. We established 3 patterns of necrosis by depth from the surface of femoral head and 5 stem angles. For these models, we evaluated biomechanical changes associated with the extent of necrosis and the stem alignment. Our results indicate that stress distribution near the bone-cement interface increased with expansion of the necrosis. The maximum stress on the prosthesis was decreased with stem angles ranging from 130° to 140°. The peak stress of cement increased as the stem angle became varus. This study indicates that resurfacing arthroplasty will have adverse biomechanical effects when there is a large extent of osteonecrosis and excessive varus or valgus implantation of the prosthesis.