Journal of Orthopaedic Surgery and Research - Latest articles

Undetected iatrogenic lesions of the anterior femoral shaft during intramedullary nailing. A Cadaveric Study.

Stamatios A Papadakis, Charalampos Zalavras, Raffy Mirzyan and Lane Shepherd — 2008-07-17

Background: The incidence of undetected radiographically iatrogenic longitudinal splitting in the anterior cortex during intramedullary nailing of the femur has not been well documented. Methods: Cadaveric study using nine pairs of fresh-frozen femora from adult cadavers. The nine pairs of femora underwent a standardized antegrade intramedullary nailing and the detection of iatrogenic lesions, if any, was performed macroscopically and by radiographic control. Results: Longitudinal splitting in the anterior cortex was revealed in 5 of 18 cadaver femora macroscopically. Anterior splitting was not detectable in radiographic control. Conclusions: Longitudinal splitting in the anterior cortex during intramedullary nailing of the femur cannot be detected radiographically.

Study of the collagen structure in the superficial zone and physiological state of articular cartilage using a 3D confocal imaging technique

Jian P Wu, Thomas B Kirk and Ming H Zheng — 2008-07-17

IntroductionThe collagen structure in the superficial zone of articular cartilage is critical to the tissue's durability. Early osteoarthritis is often characterized with fissures on the articular surface. This is closely related to the disruption of the collagen network. However, the traditional histology can not offer visualization of the collagen structure in articular cartilage because it uses conventional optical microscopy that does not have insufficient imaging resolution to resolve collagen from proteoglycans in hyaline articular cartilage. This study examines the 3D collagen network of articular cartilage scored from 0 to 2 in the scoring system of International Cartilage Repair Society, and aims to develop a 3D histology for assessing early osteoarthritis. Methods: Articular cartilage was visually classified into five physiological groups: normal cartilage, aged cartilage, cartilage with artificial and natural surface disruption, and fibrillated. The 3D collagen matrix of the cartilage was acquired using a 3D imaging technique developed previously. Traditional histology was followed to grade the physiological status of the cartilage in the scoring system of International Cartilage Repair Society. Results: Normal articular cartilage contains interwoven collagen bundles near the articular surface, approximately within the lamina splendens. However, its collagen fibres in the superficial zone orient predominantly in a direction spatially oblique to the articular surface. With age and disruption of the articular surface, the interwoven collagen bundles are gradually disappeared, and obliquely oriented collagen fibres change to align predominantly in a direction spatially perpendicular to the articular surface. Disruption of the articular surface is well related to the disappearance of the interwoven collagen bundles. Conclusion: a 3D histology has been developed to supplement the traditional histology and study the subtle changes in the collagen network in the superficial zone during early physiological alteration of articular cartilage. The fibre confocal imaging technology used in this study has allowed developing confocal arthroscopy for in vivo studying the chondrocytes in different depth of articular cartilage. Therefore, the current study has potential to develop an in vivo 3D histology for diagnosis of early osteoarthritis.

A Biomechanical Study of Plate versus Intramedullary Devices for Midshaft Clavicle Fixation

S. Raymond Golish, Jason A. Oliviero, Eric I. Francke and Mark D. Miller — 2008-07-16

IntroductionNon-operative management of midshaft clavicle fractures is standard; however, surgical management is increasing. The purpose of this study is to compare the biomechanical performance of plate versus intramedullary fixation in cyclic bending for matched pairs of cadaveric clavicles. We hypothesized that the biomechanical properties are similar. Methods: Eight sets of matched clavicles with vertical, midshaft osteotomies were prepared from fresh, frozen cadavers. A 3.5 mm dynamic compression plate or a 3.8 or 4.5 mm intramedullary device were used for fixation. Clavicles were loaded in a four-point bend at 6 different loads for 3000 cycles at 1 Hz starting with 180 N and increasing by 180 N with sampling at 2 Hz. Failure was defined as 10 mm of displacement or catastrophic construct failure prior to 10 mm of displacement. Results: Between constructs, there was a significant difference with large effect size in displacement at fixed loads of 180 N (P=0.001; Cohen's d=1.85), 360 N (P=0.033; Cohen's d=1.39), 540 N (P=0.003; Cohen's d=0.73) and 720 N (P=0.018; Cohen's d=0.72). There was a significant difference with large effect size in load at fixed displacements of 5 mm (P=0.001; Cohen's d=1.49), 7.5 mm (P=0.011; Cohen's d=1.06), and 10 mm (P=0.026; Cohen's d=0.84). Conclusions: Plate constructs are superior in showing less displacement at fixed loads and greater loads at fixed displacements over a broad range of loads and displacements with cyclic four-point bending. The clinical relevance is that plate fixation may provide a stronger construct for early rehabilitation protocols that focus on repetitive movements in the early pre-operative period.

Finger joint motion generated by individual extrinsic muscles: a cadaveric study

Ashish D Nimbarte, Rodrigo Kaz and Zong-Ming Li — 2008-07-11

Background: Our understanding of finger functionality associated with the specific muscle is mostly based on the functional anatomy, and the exact motion effect associated with an individual muscle is still unknown. The purpose of this study was to examine phalangeal joints motion of the index finger generated by each extrinsic muscle. Methods: Ten (6 female and 4 male) fresh-frozen cadaveric hands (age 55.2 +/-5.6 years) were minimally dissected to establish baseball sutures at the musculotendinous junctions of the index finger extrinsic muscles. Each tendon was loaded to 10% of its force potential and the motion generated at the metacarpophalangeal (MCP), proximal interphalangeal (PIP), and distal interphalangeal (DIP) joints was simultaneously recorded using a marker-based motion capture system. Results: The flexor digitorum profundus (FDP) generated average flexion of 19.7, 41.8, and 29.4 degrees at the MCP, PIP, and DIP joints, respectively. The flexor digitorum superficialis (FDS) generated average flexion of 24.8 and 47.9 degrees at the MCP and PIP joints, respectively, and no motion at the DIP joints. The extensor digitorum communis (EDC) and extensor indicis proprius (EIP) generated average extension of 18.3, 15.2, 4.0 degrees and 15.4, 13.2, 3.7 degrees at the MCP, PIP and DIP joints, respectively. The FDP generated simultaneous motion at the PIP and DIP joints. However, the motion generated by the FDP and FDS, at the MCP joint lagged the motion generated at the PIP joint. The EDC and EIP generated simultaneous motion at the MCP and PIP joints. Conclusions: The results of this study provide novel insights into the kinematic role of individual extrinsic muscles.

Staged surgical treatment for severe rigid scoliosis

Shi Yamin, Li Li, Wei Xing, Gao Tianjun and Zhang Yupeng — 2008-07-09

STUDY DESIGN: A retrospective study of staged surgery for severe rigid scoliosis. OBJECTIVES: To evaluate the result of staged surgery in treatment of severe rigid scoliosis and to discuss the indications. SUMMARY OF Background: DATA: Excellent outcomes of hemivertebra excision, vertebral body resection, and spinal osteotomy have been reported for angular kyphosis or kyphoscoliosis. However, their safety and effectiveness of these procedures have not been estimated. It would be difficult to correct severe and rigid spinal deformities satisfactorily by a single procedure in consideration of the neurological safety. In consequence, staged surgeries have been widely used in the treatment of severe rigid scoliosis. Nevertheless, in few papers the method of anterior releases followed by halo-pelvic traction has been mentioned. MethodS: From 1998 to 2006, 21 cases of severe rigid scoliosis with coronal Cobb angle more than 80Adegrees were treated by staged surgeries including anterior release and halo-pelvic traction as first stage surgery and posterior instrumentation and spinal fusion as second stage. Pedicle subtraction osteotomy(PSO) was added in second stage according to spine rigidity. Among the 21 patients, 8 were male and 13 female with an average age of 15.3yearsirang from 4 to 23 yearsiiThe mean pre-operative Cobb angle was 110.5Adegrees(80Adegrees-145Adegrees) with a mean spine flexibility of 13%. Radiological parameters at different operative time points were analyzed ( mean time of follow-up: 51 months) Results: : External appearance of all patients improved significantly. The average correction rate was 65.2 % ( ranging from 39.8% to 79.5%) with mean correction loss of 2.23Adegrees at the end of follow-up. No decompensation of trunk have been found. Mean distance between the midline of C7 and midsacral line was 1.19 cm A+/-0.51. Two patients had neurological complications: one patient had motor deficit and recovered incompletely. Conclusions: : Staged operation and halo-pelvic traction offer a safe and effective way in treatment of severe rigid scoliosis. Patients whose Cobb angle was more than 80Adegrees and the flexibility of the spine was less than 20% should be treated in this way, and those whose flexibility of the spine was less than 10% and the Cobb angle remained more than 70Adegrees after 1st stage anterior release and halo-pelvic traction should undergo pedicle subtraction osteotomy (PSO) in the second surgery. Key words: scoliosis, severe, two stages, pedicle subtraction osteotomy (PSO)

Subacromial impingement in patients with whiplash injury to the cervical spine

Ali Abbassian and Grey E Giddins — 2008-06-27

Background: Impingement syndrome and shoulder pain have been reported to occur in a proportion of patients following whiplash injuries to the neck. In this study we aim to examine these findings to establish the association between subacromial impingement and whiplash injuries to the cervical spine.Methods and resultsWe examined 220 patients who had presented to the senior author for a medico-legal report following a whiplash injury to the neck. All patients were assessed for clinical evidence of subacromial impingement. 56/220 patients (26%) had developed shoulder pain following the injury; of these, 11/220 (5%) had clinical evidence of impingement syndrome. Only 3/11 patients (27%) had the diagnosis made prior to evaluation for their medico-legal report. In the majority, other clinicians had overlooked the diagnosis. The seatbelt shoulder was involved in 83% of cases (p < 0.03). Conclusion: After a neck injury a significant proportion of patients present with shoulder pain, some of whom have treatable shoulder pathology such as impingement syndrome. The diagnosis is, however, frequently overlooked and shoulder pain is attributed to pain radiating from the neck resulting in long delays before treatment. It is important that this is appreciated and patients are specifically examined for signs of subacromial impingement after whiplash injuries to the neck. Direct seatbelt trauma to the shoulder is one possible explanation for its aetiology.

The occurrence of osteoarthritis at a minimum of ten years after reconstruction of the anterior cruciate ligament

Cor P van der Hart, Michel PJ van den Bekerom and Thomas W Patt — 2008-06-10

ObjectiveThe objective of this study was to evaluate the incidence of radiographic osteoarthritis in the operated knee in comparison with the contralateral knee ten years after a bone-tendon bone patellar autograft ACL-reconstruction and to evaluate to which level patients regain activity ten years after reconstruction. Methods: Fifty-three patients with ACL instability were operated arthroscopically using the central third of the patellar tendon as a bone-tendon-bone autograft. At a minimum of 10 year follow up 28/44 patients matched the inclusion criteria and could be reached for follow-up. Evaluation included a patient satisfaction evaluation using a Visual Analog Scale, physical examination (International Knee Documentation Committee score, Tegner score, Lysholm score, KT-1000 stabilometry) and a radiological evaluation (Kellgren and Fairbanks classification). Results: The patients' satisfaction, at a mean of 10,3 year follow-up, measured with a VAS score (0–10) was high with a mean of 8.5 (range 4 to 10). The KT 1000 arthrometer laxity measurements revealed in 55% of the patients an A rating (1–2 mm), in 29% a B rating (3–5 mm) and in 16% a C rating (6–10 mm). According to the Tegner score 54% of the patients were able to perform at the same activity level as pre-operatively. The mean pre-operative Tegner score was 6.8 and the mean post-operative Tegner score was 6.0 at final follow up. The Lysholm score showed satisfactory results with a mean of 91 points (range 56 to 100). According to the Kellgren and Fairbank classifications, there is a significant difference (p < 0.05) in development of OA between the ACL injured and subsequently operated knee in comparison to the contralateral knee. Conclusion: The patellar BTB ACL reconstruction does not prevent the occurrence of radiological OA after 10 years but does help the patient to regain the pre-operative level of activity.

Treatment of neuromuscular scoliosis with posterior-only pedicle screw fixation

2008-06-10

Background: To determine whether posterior-only approach using pedicle screws in neuromuscular scoliosis population adequately addresses the correction of scoliosis and maintains the correction over time. Methods: Between 2003 and 2006, 26 consecutive patients (7 cerebral palsy, 10 Duchenne muscular dystrophy, 5 spinal muscular atrophy and 4 others) with neuromuscular scoliosis underwent posterior pedicle screw fixation for the deformity. Preoperative, immediate postoperative and final follow-up Cobb's angle and pelvic obliquity were analyzed on radiographs. The average age of the patients was 17.5 years (range, 8–44 years) and the average follow-up was 25 months (18–52 months). Results: Average Cobb's angle was 78.53° before surgery, 30.70° after surgery (60.9% correction), and 33.06° at final follow-up (57.9% correction) showing significant correction (p < 0.0001). There were 9 patients with curves more than 90° showed an average pre-operative, post operative and final follow up Cobb's angle 105.67°, 52.33° (50.47% correction) and 53.33° (49.53% correction) respectively and 17 patients with curve less than 90° showed average per operative, post operative and final follow up Cobb's angle 64.18, 19.24(70% correction) and 21.41(66.64 correction); which suggests statistically no significant difference in both groups (p = 0.1284). 7 patients underwent Posterior vertebral column resection due to the presence of a rigid curve. The average spinal-pelvic obliquity was 16.27° before surgery, 8.96° after surgery, and 9.27° at final follow-up exhibited significant correction (p < 0.0001). There was 1 poliomyelitis patient who had power grade 3 in lower limbs pre-operatively, developed grade 2 power post-operatively and gradually improved to the pre-operative stage. There was 1 case of deep wound infection and no case of pseud-arthrosis, instrument failures or mortality. Conclusion: Results indicate that in patients with neuromuscular scoliosis, acceptable amounts of curve correction can be achieved and maintained with posterior-only pedicle screw instrumentation without anterior release procedure.

Passive mechanical features of single fibers from human muscle biopsies – effects of storage

Fredrik Einarsson, Eva Runesson and Jan Fridén — 2008-06-07

Background: The purpose of this study was to investigate the effect of storage of human muscle biopsies on passive mechanical properties. Methods: Stress-strain analysis accompanied by laser diffraction assisted sarcomere length measurement was performed on single muscle fibres from fresh samples and compared with single fibres from stored samples (-20°C, 4 weeks) with the same origin as the corresponding fresh sample. Basic morphological analysis, including cross sectional area (CSA) measurement, fibre diameter measurement, fibre occupancy calculation and overall morphology evaluation was done. Results: Statistical analysis of tangent values in stress-strain curves, corresponding to the elastic modulus of single muscle fibres, did not differ when comparing fresh and stored samples from the same type of muscle. Regardless of the preparation procedure, no significant differences were found, neither in fibre diameter nor the relation between muscle fibres and extra-cellular matrix measured under light microscopy. Conclusion: We conclude that muscle fibre structure and mechanics are relatively insensitive to the storage procedures used and that the different preparations are interchangeable without affecting passive mechanical properties. This provides a mobility of the method when harvesting muscle biopsies away from the laboratory.

Multiple functions of the von Willebrand Factor A domain in matrilins: secretion, assembly, and proteolysis

Yue Zhang, Zheng-ke Wang, Jun-ming Luo, Katsuaki Kanbe and Qian Chen — 2008-06-02

The von Willebrand Factor A (vWF A) domain is one of the most widely distributed structural modules in cell-matrix adhesive molecules such as intergrins and extracellular matrix proteins. Mutations in the vWF A domain of matrilin-3 cause multiple epiphyseal dysplasia (MED), however the pathological mechanism remains to be determined. Previously we showed that the vWF A domain in matrilin-1 mediates formation of a filamentous matrix network through metal-ion dependent adhesion sites in the domain. Here we show two new functions of the vWF A domain in cartilage-specific matrilins (1 and 3). First, vWF A domain regulates oligomerization of matrilins. Insertion of a vWF A domain into matrilin-3 converts the formation of a mixture of matrilin-3 tetramer, trimer, and dimer into a tetramer only, while deletion of a vWF A domain from matrilin-1 converts the formation of the native matrilin-1 trimer into a mixture of trimer and dimer. Second, the vWF A domain protects matrilin-1 from proteolysis. We identified a latent proteolytic site next to the vWF A2 domain in matrilin-1, which is sensitive to the inhibitors of matrix proteases. Deletion of the abutting vWF A domain results in degradation of matrilin-1, presumably by exposing the adjacent proteolytic site. In addition, we also confirmed the vWF A domain is vital for the secretion of matrilin-3. Secretion of the mutant matrilin-3 harbouring a point mutation within the vWF A domain, as occurred in MED patients, is markedly reduced and delayed, resulting from intracellular retention of the mutant matrilin-3. Taken together, our data suggest that different mutations/deletions of the vWF A domain in matrilins may lead to distinct pathological mechanisms due to the multiple functions of the vWF A domain.