Factors That Determine Supination Strength Following Distal Biceps Repair.

BACKGROUND: Supination weakness commonly occurs after a distal biceps repair. The goal of this study was to identify factors that could influence postoperative supination strength through a full arc of forearm rotation. METHODS: Fifteen patients were prospectively studied and underwent a biceps repair using a posterior approach; this cohort was compared with a randomized selection of 17 anterior repair subjects. All patients underwent postoperative magnetic resonance imaging (MRI). Quantitative MRI analysis determined the insertion site angle of the tendon and supinator fat content. Supination strength was measured in 3 forearm positions. A multiple linear regression analysis was performed to determine the effect of all factors on supination strength. RESULTS: The anterior group had a significantly higher nonanatomic insertion site angle of the tendon than the control group and the posterior group (p < 0.001). The posterior group had significantly greater supinator fat content (p ≤ 0.019) than both the control group and the anterior group. After repair, the posterior group had significantly greater supination strength than the anterior group (p = 0.027). Multiple regression analysis (r = 0.765) found that an anatomic reinsertion of the ruptured tendon (ß = 1.159; p < 0.001), posterior approach (ß = 0.484; p = 0.043), and limited supinator muscle fat content (ß = 0.360; p = 0.013) were significant predictors of the restoration of supination strength in 60° of supination. CONCLUSIONS: Future directions for distal biceps tendon repair techniques should focus on restoring an anatomic reattachment site while limiting supinator damage. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Fine-needle aspiration cytology of disseminated Kaposi sarcoma of the bone in an AIDS patient.

BACKGROUND: Kaposi sarcoma (KS) is a vascular neoplasm associated with human herpesvirus 8 (HHV-8). Skin and mucous membranes are the most common sites, but other organs may be involved. Skeletal KS is rare and occurs either by direct spread of mucocutaneous lesions or through dissemination. Patients present with bone pain and lytic lesions for which they may undergo fine-needle aspiration (FNA). While there are about 70 published case reports of skeletal KS, there is limited literature specifically describing its cytomorphology. Our literature search yielded only a single prior reported case of FNA biopsy of skeletal KS in a Nigerian AIDS patient. CASE: We present a case of disseminated KS of the axial skeleton in a 45-year-old African-American man with AIDS which was diagnosed on FNA cytologic examination. The patient presented with multiple lytic lesions in the axial skeleton. The aspirate, core-needle biopsy and touch imprint cytology of a bone lesion demonstrated clusters of spindle and epithelioid cells in radial and streaming arrangement with indistinct intercytoplasmic borders, elongated nuclei, fine chromatin and inconspicuous nucleoli. Immunohistochemical studies revealed positivity for HHV-8 and vascular markers. The cytomorphologic and ancillary features of the case are presented and discussed.

Effect of lesser tuberosity osteotomy size and repair construct during total shoulder arthroplasty.

BACKGROUND: Lesser tuberosity osteotomy has been shown to decrease postoperative subscapularis dysfunction. The purpose of this study was to determine the effect of osteotomy thickness and suture configuration on repair integrity. MATERIALS AND METHODS: One side of 12 matched-pair cadaveric shoulders was randomly assigned to either a thick osteotomy (100% of lesser tuberosity height) or a thin osteotomy (50% of height). Both sides of the matched pairs were given the same repair, either (1) compression sutures or (2) compression sutures plus 1 tension suture. This created 4 groups of 6 paired specimens. Computed tomography imaging was used to measure tuberosity dimensions before and after osteotomy to validate fragment height and area. The repairs were loaded cyclically and then loaded to failure. A video system measured fragment displacement. The percent area of osteotomy contact was calculated from the computed tomography and displacement data. RESULTS: The average initial displacement was less in the thin osteotomy groups (P = .011). Adding a tension suture negated this difference. A significant number of thin repair sites compared with thick repair sites remained intact during load-to-failure testing (P = .001). No difference occurred because of maximum load between the repair groups (P = .401), and construct stiffness was greater when a tension suture was used (P = .032). The percent area of osteotomy contact showed no differences between the osteotomy (P = .431) and repair (P = .251) groups. CONCLUSION: The study showed that thin osteotomies displaced less than thick osteotomies. Adding a tension band improved construct stability and eliminated some failure modes. Our ideal repair was a thin wafer with both tension and compression sutures. This construct had smaller total displacement, a high osteotomy percent contact area, and a high maximum load.

Repaired distal biceps magnetic resonance imaging anatomy compared with outcome.

BACKGROUND: This study examined the magnetic resonance imaging (MRI) appearance of an anterior incision distal biceps tendon repair and evaluated the association between appearance and outcome. MATERIALS AND METHODS: Nineteen patients were randomly recruited to undergo an elbow MRI from a single-surgeon series of distal biceps repairs using an anterior approach. Tendon healing was evaluated by the integrity of the repair, the amount of heterogeneity within the tendon substance, and the presence of heterotopic bone. The angle of tendon insertion on the tuberosity was used to quantify the tendon location from the MRI in the patients and in 10 healthy volunteers. All patients completed the Disabilities of Arm, Shoulder and Hand (DASH) and a visual analog pain scale (VAPS), and 17 patients underwent isometric supination strength testing. MRI findings were statistically compared with the outcome scores. RESULTS: All of the repairs healed to cortical bone. High intrasubstance heterogeneity or heterotopic bone was present in 11 patients (58%). The insertion site angle of the repaired tendons was 73° more anterior than the uninjured controls (P < .001). Average DASH was 7.7 (range, 0-49.2) and VAPS was 0.7 (range, 0-5). At 60° of forearm supination, supination strength was 67% of the uninjured side (P < .01). No significant differences in DASH or VAPS scores were found between groups based on tendon appearance. CONCLUSIONS: The distal biceps tendon predictably heals to cortical bone but demonstrates a wide variability in overall morphology that does not influence DASH or VAPS scores. A significant decrease in strength at 60° of supination appears to be an effect of an anterior tendon reattachment location.

Clinical and magnetic resonance imaging outcomes following platelet rich plasma injection for chronic midsubstance Achilles tendinopathy.

BACKGROUND: The successful treatment of chronic mid-substance Achilles tendinopathy remains elusive. Approximately 25% to 50% of patients fail conservative treatment modalities. Scientific evidence has supported the use of platelet rich plasma (PRP) in the tendon healing process, however despite initial promise there is a paucity of clinical data to validate a role for PRP in the treatment of tendon disorders including chronic midsubstance Achilles tendinopathy. METHODS: As an alternative to operative treatment, our practice offers patients with chronic midsubstance Achilles tendinopathy intratendinous injection of PRP. We retrospectively reviewed all patients treated for Achilles tendinopathy with PRP injection over a 2-year period. Baseline and post injection functional scores including the Foot and Ankle Ability Measure (FAAM), Foot and Ankle Ability Measure - Sports (FAAMS), and the Short Form health survey (SF-8) were examined. Patients also underwent post-injection magnetic resonance imaging (MRI), which were compared to available pre-injection MRI data. RESULTS: Ten patients were identified for this study. Pre- and postinjection functional outcome scores were available for eight of ten patients. The average SF-8 score improved from 24.9 to 30.0, the average FAAM score improved from 55.4 to 65.8, and the average FAAMS score improved from 14.8 to 17.4. Complete MRI data was available for six patients. Only one in six Achilles tendons demonstrated qualitative MRI improvement post-injection. CONCLUSION: Patients who received PRP injection demonstrated modest improvement in functional outcome measures, however MRI appearance of diseased Achilles tendons remained largely unchanged following PRP injection.

Hip biomechanics: importance to functional imaging.

Although well recognized the hip joint is not well understood. In many respects knowledge of the hip is similar to that of the knee several decades ago. Increased understanding of the hip's structure and function will improve our ability to diagnose and treat pre-end-stage hip joint disease. This article describes relevant anatomy and mechanics and details the crucial role that imaging plays in current assessments of hip function.