Intercondylar synovial septum in two patients with nail-patella syndrome.

This case report describes the arthroscopic findings in two patients with nail-patella syndrome (NPS). In both cases, a midline synovial septum was encountered that completely subdivided the knee into medial and lateral compartments. One patient required two subsequent arthroscopic procedures, and the synovial septum was found to have recurred even after it had been resected at the initial surgery. The etiology and clinical significance of this anatomic anomaly are unknown, however, surgeons should be aware of its existence and the potential difficulties it may present during knee arthroscopy in patients with NPS.

Repair of lesser tuberosity osteotomy for shoulder arthroplasty: biomechanical evaluation of the Backpack and Dual Row techniques.

BACKGROUND: Subscapularis dysfunction following total shoulder arthroplasty can result in permanent loss of function. The lesser tuberosity osteotomy (LTO) has been proposed as a method which utilizes bone-to-bone healing to improve subscapularis function. This study evaluates the biomechanical properties of two described techniques for LTO repair. We hypothesized that a Dual Row repair would be stronger and demonstrate less cyclic displacement than a Backpack repair. MATERIALS AND METHODS: Ten matched pairs of cadaveric humeri were dissected, leaving the subscapularis intact, and a lesser tuberosity osteotomy was performed. Matched shoulders were randomized to either a Backpack repair or a Dual Row repair. Repairs were subjected to cyclic loading to 180 N for 500 cycles, followed by ramp-up loading to ultimate failure. Clinical failure was defined as displacement >5 mm after 500 cycles. RESULTS: Displacement after 500 cycles was significantly greater for the Backpack repair (6.9 mm) than for the Dual Row repair (4.6 mm) (P = .007). Most displacement occurred on the first cycle (Backpack, 4.6 mm; Dual Row, 2.1 mm) (P < .001). There was a trend toward a higher clinical failure rate for the Backpack repair (8/10) than the Dual Row repair (3/10). Ultimate tensile strength was significantly greater for the Dual Row repair (632.3 N) than for the Backpack repair (510.9 N) (P = .01). CONCLUSION: The Dual Row technique is significantly stronger and demonstrates less cyclic displacement than the Backpack technique. Clinical studies are needed to determine the impact of LTO repair technique on subscapularis function following shoulder arthroplasty.

Femoral head size and wear of highly cross-linked polyethylene at 5 to 8 years.

UNLABELLED: Wear of highly cross-linked polyethylene is reportedly independent of head size. To confirm that observation we asked in our population whether head size related to wear with one type of electron beam highly cross-linked polyethylene. Of 146 hips implanted, we evaluated complete clinical and radiographic data for 90 patients (102 hips or 70%). The minimum followup was 5 years (mean, 5.7 years; range, 5-8 years). The head size was selected intraoperatively based on the size of the acetabular component and presumed risk of dislocation. Polyethylene wear measurements were performed in one experienced laboratory using the method of Martell et al. There was no hip with pelvic or femoral osteolysis. The median linear wear rate was 0.028 mm/year (mean, 0.04 mm/year), and the median volumetric wear rate was 25.6 mm(3)/year (mean, 80.5 mm(3)/year). Median total volumetric wear was 41.0 mm(3) (mean, 98.5 mm(3)). We found no association between femoral head size and the linear wear rate, but observed an association between larger (36- and 40-mm) head size and volumetric wear rate and total volumetric wear. Although the linear wear rate of polyethylene was not related to femoral head diameter, there was greater volumetric wear (156.6 mm(3)/year) with the 36- and 40-mm heads. Pending long-term studies of large head sizes, we advise caution in using larger femoral heads in young or active patients and in those with a low risk of dislocation. LEVEL OF EVIDENCE: Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Shortcuts in arthroscopic knot tying: do they affect knot and loop security?

BACKGROUND: Shortcuts for throwing 3 alternating reversed half-hitches on alternating posts (RHAPs), in which the post is switched by alternating strand tension to "flip" the knot, have been advocated but never validated in a biomechanical study. HYPOTHESIS: Shortcut tying techniques will affect knot security or loop security. STUDY DESIGN: Controlled laboratory study. METHODS: A single surgeon tied 90 knots using No. 2 FiberWire through an arthroscopic cannula. Half had a static "surgeon's base," and half had a Tennessee slider base. Three techniques were used to create 3 RHAPs: (1) rethreading, (2) knot "flipping" where half-hitches were tensioned by past-pointing, and (3) knot "flipping" where half-hitches were tensioned by alternating past-pointing and over-pointing. Each knot was subjected to a preload of 5 N, followed by 1000 cycles of 5 N to 45 N at 1 Hz, and a single load to failure. RESULTS: When compared with Tennessee knots, surgeon's knots had a lower incidence of knot slippage and catastrophic failure as well as higher loads to clinical and ultimate failure. Shortcut techniques did not affect the properties of surgeon's knots. However, when used to secure Tennessee knots, past-pointing decreased load to clinical failure and ultimate load to failure. Over-pointing increased the incidence of knot slippage and catastrophic failure and decreased load to clinical failure and ultimate load to failure. Loop security was marginally increased by both past-pointing and over-pointing. CONCLUSION: When all tying techniques are considered, surgeon's knots outperform Tennessee sliding knots. Shortcut techniques do not alter the properties of surgeon's knots. However, when used to secure Tennessee sliding knots, shortcuts lead to unacceptably high rates of knot slippage and catastrophic failure as well as decreased knot security. CLINICAL RELEVANCE: The outcomes of arthroscopic rotator cuff or labral repairs can be compromised when using shortcut tying methods to secure sliding Tennessee knots.

Tendon disorders of the foot and ankle, part 3: the posterior tibial tendon.

This article provides a review of posterior tibial tendon pathology and the authors' preferred management. The tibialis posterior musculotendinous unit is the most powerful inverter of the foot and an important dynamic stabilizer of the arch. In the stance phase of the gait cycle, it serves as an initiator of both ankle plantar flexion and subtalar inversion. This creates a rigid midfoot by stabilizing the transverse tarsal joint, and allows for increased power generation by the gastrocsoleus complex through toe-off. Injuries to the posterior tibialis tendon include traumatic laceration and dislocation, as well as tenosynovitis and tendinopathy, which can lead to attenuation and rupture. If these injuries are not addressed, significant clinical deformity and disability can result.

Management of failed biceps tenodesis or tenotomy: causation and treatment.

The purpose of this paper is to review the management of long head biceps tendon pathology, with a particular emphasis on a prior failed biceps tenotomy or tenodesis. Failed biceps tenotomy generally results from a lack of thorough preoperative discussion of potential outcomes rather than from technical problems. Patients with unsatisfactory results can be treated with conversion to a biceps tenodesis. Failed biceps tenodesis is usually recognized with persistent pain in the area of the bicipital groove, often caused by either the mechanical failure of the tenodesis or associated shoulder pathology that is not addressed at the time of the primary surgery. Operative treatment options include revision tenodesis or biceps tenotomy. The subpectoral approach provides excellent versatility and ability to meet technical objectives when performing revision tenodesis, by removing the tendon completely from the groove and preserving biceps function.

Tendon disorders of the foot and ankle, part 1: peroneal tendon disorders.

Pathologic abnormality of the peroneal tendons is an uncommon but underappreciated source of lateral hindfoot pain and dysfunction that can be difficult to distinguish from lateral ankle ligament injuries. When left untreated, peroneal tendon disorders can lead to persistent lateral ankle pain and substantial functional problems. Unfortunately, the treatment recommendations for these disorders are primarily based on case series and expert opinion. The goals of this review are to develop a current understanding of the anatomy and diagnostic evaluation of the peroneal tendons, and to present current treatment options and the authors' preferred surgical techniques for operative management of peroneal tendon lesions.

Tendon disorders of the foot and ankle, part 2: achilles tendon disorders.

Disorders of the Achilles tendon include both acute and chronic ruptures as well as a spectrum of chronic overuse injuries involving inflammatory and degenerative changes within the tendon and surrounding tissues. These injuries are relatively common in athletes as well as among the general population. There is no consensus on the optimal treatment of Achilles tendon disorders. The goals of this review are to develop a current understanding of the anatomy and diagnostic evaluation of the Achilles tendon, and to present current treatment options and the authors' preferred surgical techniques for operative management of Achilles tendon disorders.

Operative treatment for peroneal tendon disorders.

Peroneal tendon disorders are rare, are frequently missed, and can be a source of lateral ankle pain. Magnetic resonance imaging is the standard method of radiographic evaluation of peroneal tendon disorders; however, diagnosis and treatment are based primarily on the history and physical examination. Peroneal tenosynovitis typically responds to conservative therapy, and operative treatment is reserved for refractory cases. Operative treatment is frequently required for peroneal tendon subluxation and consists of anatomic repair or reconstruction of the superior peroneal retinaculum with or without deepening of the retromalleolar groove. Operative treatment of peroneal tendon tears is based on the amount of remaining viable tendon. Primary repair and tubularization is indicated for tears involving <50% of the tendon, and tenodesis is indicated for tears involving >50% of the tendon.