Effect of joint motion on safety of portals in posterior ankle arthroscopy.

PURPOSE: The purpose of this study was to determine the anatomic relation of the neural structures posteriorly crossing the ankle by use of classical ankle arthroscopy posterior portals and hindfoot endoscopy portals. The effect of ankle and hindfoot motions on portal-nerve distance was also determined. METHODS: This study included 20 feet and ankles in 20 adult volunteers who had no complaints regarding their ankle joints. To obtain 6 fixed positions of the ankle and hindfoot (neutral-neutral, neutral-varus, neutral-valgus, dorsiflexion-neutral, dorsiflexion-varus, and dorsiflexion-valgus) during magnetic resonance imaging examination, feet were positioned in a polycaprolactone splint that was shaped before examination. Magnetic resonance imaging examinations were performed at all 6 positions, and the shortest distance between the sural and posterior tibial nerves to the portals was measured at 2 different levels. RESULTS: The mean distance between the posterior tibial nerve and the posteromedial portal was 16.5 +/- 5.6 mm and that between the sural nerve and the posterolateral portal was 13.1 +/- 3 mm at the hindfoot portal level. At the level of the posterior ankle arthroscopy portal, the mean distance from the posterior tibial nerve to the posteromedial portal line was 13.3 +/- 4.6 mm and that from the sural nerve to the posterolateral portal line was 9.7 +/- 2.9 mm. The differences in distances were statistically significant (P < .001) according to the paired t test. We determined that the sural nerve approached the posterolateral portal in the dorsiflexion-varus (P = .026), dorsiflexion-valgus (P = .014), dorsiflexion-neutral (P < .001), and neutral-varus (P = .035) positions, and all differences were statistically significant. CONCLUSIONS: We found that the posterior medial and lateral portals created at the level of the tip of the fibula as described by van Dijk et al. while the foot was in a neutral-neutral position provided the greatest margin of safety. We found no advantage of placing the ankle and hindfoot in different positions to avoid neurologic complications. CLINICAL RELEVANCE: These findings suggest that neurovascular structures draw away from the posterior portals of ankle arthroscopy distally; by lowering the level of portals toward the tip of the fibula and positioning the foot at neutral, arthroscopic surgeons will decrease the risk of iatrogenic lesions.

[Osteochondral allograft transplantation in the knee]. / Dizde osteokondral allogreft transplantasyonu.

Despite significant improvements for the past 20 years in the treatment of full-thickness chondral defects with the use of chondroprotective biological methods (microfracture, autologous chondrocyte transplantation, osteochondral autograft, and periosteal graft), the treatment of large osteochondral defects in young and physically active population is still challenging. Alternatives for the treatment of chondral defects exceeding 3 cm in size are limited, and among them, allografts have been used longer than any other treatment methods with the most favorable results. The success rates for osteochondral allograft transplantation have been reported as 95%, 71%, and 66% at 5, 10, and 20 years, respectively. Factors that adversely affect long-term results include advanced age, allograft transplantation to both sides of the joint, inappropriate loading, osteoarthritis, and osteonecrosis due to steroid use. Today, as a result of improvements in tissue-organ transplantation, increased availability of fresh tissue from donors, and increased demand from patients and physicians, there has been growing interest in the use of osteochondral allografts in selected patients to delay arthroplasty for chondral defects.

Reconstruction of quadriceps tendon with Achilles tendon allograft in older children with congenital dislocation of the knee.

This is a case report of two children with congenital dislocation of the knee. They have been treated surgically with Z-lengthening of the quadriceps tendon and additional reconstruction of the quadriceps tendon with Achilles tendon allograft to fill in the remaining average 6 cm gap of the tendon. The patients were two girls, 6 and 9 years old. One of them had an operative treatment previously with a tendon lengthening procedure and it was failed and the other patient was untreated before. Preoperatively, untreated case was unable to walk. The other patient was limping. None of them was able to flex their knees beyond the neutral extension position. Postoperatively, both patients were able to walk and the knees were reduced to a range of motion of 0 degrees -95 degrees of flexion. The mean follow-up time was 20 months.