No differences in knee kinematics between active and passive flexion-extension movement: an intra-operative kinematic analysis performed during total knee arthroplasty.

PURPOSE: The objective of the present study was to acquire and compare by the use of a navigation system the intra-operative flexion-extension movement of the knee performed actively by the patient and passively by the surgeon before and after a total knee arthroplasty (TKA) implantation. METHODS: A cohort of 31 patients with primary knee osteoarthritis (OA), candidate for TKA underwent intra-operative kinematics assessment with a commercial navigation system before and after the definitive implant positioning of a Cruciate Retaining (CR) Mobile Bearing (MB) prostheses. The kinematical data were acquired while surgeon performed the flexion-extension movement (passive ROM - pROM), and while the patient performed it (active ROM - aROM). Differences between pre- and post- implantation and between active and passive motions, were statistically analyzed using paired Student t-tests (p = 0.05). RESULTS: No statistically significant difference were found between aROM and pROM with paired Student t-test regarding internal-external rotation and anterior-posterior translation of the femoral component with respect to the tibia during flexion-extension movement before and after TKA implant (p > 0.05). CONCLUSIONS: Active muscle contraction seems to not significantly affect TKA kinematics. The ROM performed by the surgeon during operation resemble the movement actively performed by the patient. The clinical relevance of this study further supports the use of CAS system in performing intra-operative analysis concerning knee biomechanics.

Isolated reconstruction of the medial patellofemoral ligament with autologous quadriceps tendon.

BACKGROUND: Since the role of the medial patellofemoral ligament (MPFL) as the primary soft-tissue restraint against lateral patellar translation has been recognized, several different reconstruction procedures for the treatment of patellar instability have been proposed over recent years. Many of these techniques require bony procedures and hardware fixation at the patellar and femoral side, leading to complications as described previously in the literature. The purpose of the present study is to describe the technique of isolated MPFL reconstruction using the quadriceps tendon and report the results at a mean follow-up of 38 months. The hypothesis is that this technique, not requiring drilling of bone tunnels on the patellar and femoral side, may be a "simple and safe" mean to manage patellar instability, giving good clinical results with low complication rate in selected patients with normal osseous anatomy. MATERIALS AND METHODS: Sixteen consecutive patients (9 male, 7 female; mean age 22 years) with chronic patellar instability underwent medial patellofemoral reconstruction with the superficial layer of the quadriceps tendon. All the patients were evaluated preoperatively and postoperatively by physical examination and subjectively with Kujala and Lysholm scores. RESULTS: The average follow-up was 38 months (range 28-48 months). No recurrent episodes of dislocation or subluxation and no complications occurred. The mean Kujala score increased from 35.8 preoperatively to 88.8 postoperatively and the Lysholm score improved from 43.3 preoperatively to 89.3 postoperatively. CONCLUSIONS: Isolated MPFL reconstruction using an autologous quadriceps tendon and not requiring bone tunnels, may be a safe, simple and effective procedure for the treatment of patellar instability without complications such as patellar fracture as reported by clinical studies using hamstring grafts. For the same reason it may also be indicated in skeletally immature patients. LEVEL OF EVIDENCE: Level IV.

Real life thromboprophylaxis in orthopedic surgery in Italy. Results of the GIOTTO study.

INTRODUCTION: Data from a prospective, multicentre observational study (Studio GIOTTO) were analyzed to determine, in clinical practice, the pattern of VTE prophylaxis and adherence to international guidelines recommendations in major orthopedic surgery (MOS) - including total hip arthroplasty (THA), total knee arthroplasty (TKA) and hip fracture surgery (HFS) - and knee arthroscopic surgery (KAS). METHODS: In 2010, the first consecutive 30 patients hospitalized in Italian centers for MOS and the first 15 for KAS were enrolled and treated according to the usual practice. RESULTS: 2010 patients were admitted for MOS (577 TKA, 787 THA and 646 HFS) and 993 for KAS; mean ± SD age was 71.7 ± 8 and 43.0 ± 15 years, and female prevalence was 65.6% and 31.1% in MOS and KAS, respectively. Most (66.7%; 95% CI: 65-69%) patients admitted for MOS received a combined VTE prophylaxis, consisting of both pharmacological and physical tools, and 33.2% (95% CI: 31-35%) only pharmacological. For KAS figures were 23.7 (95% CI: 21-26%) and 75.3% (95% CI: 72-77%). Most MOS (91%; 95% CI: 89-92%) and KAS (95% CI: 98-100%) patients receiving pharmacological thromboprophylaxis were treated with low molecular weight heparin (LMWH), for (median) 40 days in TKR, 39 days in THR, 44 in HFS, and 16 in KAS. Patients receiving <35 days of LMWH prophylaxis among those undergoing THR and HFS were 8.9% and 5.9%, respectively. CONCLUSION: Although most patients undergoing orthopedic surgery received VTE prophylaxis, a gap between clinical practice and international guideline recommendations was observed. The reduced adherence to guideline recommendations is relevant for certain choices like type and duration of VTE, and physicians' behavior may reflect the changing approach of guidelines in their different editions.

Medium term follow up of the Biodynamic neck sparing prosthesis.

Hip resurfacing (HR) and neck sparing prostheses (NSP) have been advocated for the treatment of arthritis in younger patients. Some complications following HR have been documented in the recent literature, but NSP are not yet supported by clinical follow-up studies of sufficient duration. We present an assessment of the neck sparing "Biodynamic" prosthesis. 153 patients were evaluated in a longitudinal cohort prospective study, with survival analysis, clinical score and radiographic assessment of stability and osteointegration at 41.8 months average follow up. Survival and clinical outcome were similar to most traditional prostheses in the literature. On radiographic analysis we recorded good neck preservation and osteointegration. Only two stem failures were recorded. Poor clinical outcome was related to misalignment of prostheses implanted during the 'learning curve'. The NSP system described may be a good alternative to HR for younger patients. The system is characterized by good survival and clinical and radiographic outcome combined with bone stock preservation.

Symptomatic snapping knee from biceps femoris tendon subluxation: an unusual case of lateral pain in a marathon runner.

Snapping biceps femoris syndrome is an uncommon cause of lateral knee pain and may be difficult to diagnose, resulting in unsuccessful surgical intervention. In this report, we present an unusual case of a 37-year-old male marathon runner with unilateral snapping knee secondary to dislocation of the long head of the biceps femoris over the fibular head during knee flexion. The pain was great enough to interfere with his ability to practice sport. Possible causes of symptomatic snapping knee include multiple intra-articular or extra-articular pathology. Biceps femoris snapping over the fibular head is a rare condition. Reported causes include an anomalous insertion of the tendon into the tibia, trauma, and fibular-head abnormality. However, none of those conditions accounted for his symptoms. Failing conservative treatment, the patient underwent surgery for partial resection of the fibular head, with subsequent sudden resolution of symptoms and return to sport. Accurate knowledge and management of this rare condition is mandatory to avoid inappropriate therapy and unnecessary surgical procedures.

Unusual complication of central venous catheter in hemodialysis.

A case of a partial rupture of a cuffed central venous catheter (CVC) implanted in the femoral vein with the purpose of being used for chronic hemodialysis is described in a 74-year-old female patient. Of relevance is that the CVC described was from the same manufacturer as the previous one that had lasted 12 years.