Biceps femoris snapping and friction on the fibular head secondary to abnormal distal tendon insertion: 15 cases and a literature review.

INTRODUCTION: Abnormal biceps femoris distal tendon insertion can cause tendon snapping, as is well-known in the literature. The presenting symptom is lateral knee pain, often during sports activities and cycling in particular. The present study tested two hypotheses: abnormal biceps femoris insertion on the fibular head may cause painful friction without clinical snapping, whether visible, audible or palpable; surgical correction achieves good results for pain and return to sport, regarding both snapping and friction. MATERIAL AND METHODS: Between 2006 and 2017, 11 patients were managed for pain secondary to abnormal biceps femoris insertion. In 4 cases, pain was bilateral, resulting in a total of 15 knees: 9 with snapping (in 6 patients), and 6 with friction syndrome without snapping (in 5 patients). All 6 patients with snapping were male, with a mean age of 29 years. Friction without snapping concerned 3 female and 2 male patients, with a mean age of 30 years. Study data included type and level of sport, clinical signs, imaging, type and results of treatment, and type of abnormality. RESULTS: The insertion abnormality consisted in excessively anterior insertion in the fibular arm in 6 cases, in predominantly tibial insertion in 2 cases, and in isolated tibial insertion in 4 cases. Surgery mainly consisted inrelease and reinsertion of the distal biceps femoris tendon (in 7 cases). All patients were able to return to sport. The mechanism underlying snapping and friction was the same: distal biceps tendon friction on the fibular head secondary to unduly anterior fibular or predominantly or exclusively tibial insertion. DISCUSSION: The literature reports 24 cases, all of snapping, with between 1 and 3 cases per author. These findings were compared with the present results. With or without snap, symptoms are secondary to abnormal tendon insertion and to activity or sport requiring repeated knee flexion greater than 90°. CONCLUSIONS: (1) Case studies show that lateral knee pain by friction on the fibular head is not systematically accompanied by snapping. (2) In all reports and in the present series, surgery was highly effective on snapping and pain, and patients returned to sport at their previous level. LEVEL OF EVIDENCE: IV.

The natural progression of symptomatic humeral head osteonecrosis in adults with sickle cell disease.

BACKGROUND: Osteonecrosis of the humeral head is a frequent complication in adults with sickle cell disease. However, little is known about the rate of, and the factors influencing, progression of symptomatic shoulder osteonecrosis in patients with this disease. METHODS: Eighty-two adult patients with sickle cell disease and symptomatic osteonecrosis of the humeral head (104 shoulders) were identified with magnetic resonance imaging (MRI) between 1985 and 1993. Nineteen of the eighty-two patients were homozygous for hemoglobin S (S/S genotype), thirty-seven had hemoglobin S/hemoglobin C (S/C), and twenty-six had hemoglobin S/beta-thalassemia (S/T). Shoulder osteonecrosis was graded with the method of Cruess with an adaptation for MRI as proposed by Steinberg et al. for hip osteonecrosis. Annual radiographs were obtained. At the initial evaluation, thirty-eight symptomatic shoulders were designated as stage I (with osteonecrosis seen only on MRI), forty-two symptomatic shoulders were designated as stage II (radiographic evidence without collapse), and twenty-four symptomatic shoulders were designated as stage III or IV (a crescent line or collapse). RESULTS: Partial or total repair with a decrease in the size of the osteonecrotic lesion or in the stage was never observed on MRI. At the time of the most recent follow-up (average, twenty years; range, fifteen to twenty-four years), collapse had occurred in eighty-nine shoulders (86%). The mean interval between the onset of pain and collapse was six years (range, six months to seventeen years; median, eight years). Of the 104 symptomatic shoulders, sixty-three (61%) with collapse worsened clinically until surgical treatment was needed. The principal risk factors for development of shoulder osteonecrosis in adults with sickle cell disease were the presence of hip osteonecrosis and the S/T or S/C genotype. The rate and risk of progression of the lesion until collapse occurred were significantly related to the S/S genotype, to a stage of II, to a large size of the osteonecrotic lesion, and to a medial or posterior location of the lesion. CONCLUSION: Untreated symptomatic shoulder osteonecrosis related to sickle cell disease has a high likelihood of progressing to humeral head collapse, and the natural evolution in the long term requires surgical treatment for many of these patients.

Reliability analysis for manual measurement of coronal plane deformity in adolescent scoliosis. Are 30 x 90 cm plain films better than digitized small films?

For several years, digitized small radiographs are used to measure Cobb angle in idiopathic scoliosis. The interobserver and intraobserver Cobb angle measurement variability associated with small radiographs were compared with measurement variability associated with the long-cassette radiographs. Twenty adolescent patients with a double major idiopathic scoliosis had erect full-spine p-A radiographs and Cobb angle measurements performed by eight different observers on a 30 x 90 cm plain-film radiograph and a digitized 14 x 42 cm image. Inter-observer and intra-observer reliability using each techniques were assessed using a paired t-test, Spearman rank correlation study and intraclass correlation coefficients. The angle variability between small film and plain-film measurements was assessed using the same methods. Intra-observer and inter-observer study showed good reliability using both techniques. The comparison between small films and plain-films measurements showed very good agreement with an intraclass correlation coefficient of 95% and confidence interval between 0.962 and 0.972. In our study, Cobb angle determination was not found to vary significantly with film size. The small film image used for full-spine radiographs in our institution allows manual Cobb angle measurements to be performed. A study is currently conducted in our institution to determine if a computer-assisted measurement method significantly improves Cobb angle measurements reliability in routine practice compared with manual measurements of Cobb angles on small films.