Shortening of the patellar tendon length does not influence the patellofemoral alignment in a cadaveric model.

INTRODUCTION: Anterior cruciate ligament (ACL) reconstruction with the use of autograft tissue represents the standard treatment. The use of a bone-patellar tendon-bone transplant for symptomatic ACL deficiency achieves good long-term results. The purpose of the study was to investigate in a cadaveric model whether reproducible patellar tendon shortening changes the patellofemoral alignment. MATERIALS AND METHODS: Using five cadaveric knees, an MRI investigation was performed with the patellar tendon left unchanged, shortened 5 mm and shortened 10 mm, respectively, in both 20 and 45 degrees of knee flexion. The lateral patellofemoral and the congruence angles were measured and compared using a one-way analysis of variance for repeated measurements. RESULTS: Shortening the patella tendon by approximately 20% did not significantly influence the patellofemoral alignment. CONCLUSION: Although anterior cruciate ligament-reconstruction using the patellar tendon has become a standard procedure, postoperative problems such as anterior knee pain, and patellofemoral osteoarthritis occur quite often. In this cadaver study we did not find a significant difference for the patellofemoral alignment, irrespective of the patellar tendon length.

Arthroscopic excision of the radial head: Clinical outcome in 12 patients with post-traumatic arthritis after fracture of the radial head or rheumatoid arthritis.

PURPOSE: We performed arthroscopic radial head excision in a series of patients with either post-traumatic arthritis after a radial head fracture or rheumatoid arthritis of the elbow as an expanded indication for elbow arthroscopy. The purpose of the study was to critically examine the results of arthroscopic chondroplasty of the radial head to determine the safety and effectiveness of the procedure. TYPE OF STUDY: Outcome study and retrospective analysis. METHODS: From 1990 to 1997, arthroscopic radial head resection was performed in 12 patients with either post-traumatic arthritis (n = 10, Mason type II or III) or with rheumatoid arthritis (n = 2). Functional outcome and radiographs were analyzed after a mean follow-up period of 39 months (range, 12 to 97 months). Elbow arthroscopy was performed using a standardized technique. The anterior three quarters of the radial head and 2 to 3 mm of the radial neck were resected with the abrader in the anterolateral portal and the arthroscope in the proximal medial portal. For resection of the posterior portion of the radial head, the abrader may be transferred to the mediolateral portal. This permits resection of the remnants of the radial head posteriorly and also at the proximal radioulnar joint. RESULTS: Preoperatively, patients lacked 23 degrees (range, 5 degrees to 40 degrees ) of extension of the elbow on average. Mean flexion was 111 degrees (range, 60 degrees to 145 degrees ). Patients had unrestricted pronation (limitation of 5 degrees in 2 patients). Two patients had a lack of supination of 15 degrees and 30 degrees. Mean follow up was 39 months (range, 12 to 97 months). Postoperatively, patients lacked 9 degrees (range, 0 degrees to 20 degrees ) of extension of the elbow on average. Mean flexion was 136 degrees (range, 90 degrees to 150 degrees ). No patient had subjective or objective evidence of instability of the elbow. All patients except one reported significant improvement in pain relief and complete relief of mechanical symptoms. CONCLUSIONS: This technically demanding surgical procedure should be reserved for situations of persistent, restricted range of motion and chronic pain. Arthroscopic radial head resection combined with arthroscopic synovectomy relieves elbow stiffness. The surgeon is able to deal with the intrinsic joint pathology, as well as with accompanying symptoms such as synovitis, capsular contracture, or loose bodies.

Accuracy of pressure and flow capacities of four arthroscopic fluid management systems.

PURPOSE: The present study was conducted to evaluate 4 different fluid delivery systems: Arthrex AR-6450, Stryker 1.5L High Flow Pump, Arthro FMS 4, and Acufex InteliJet. Their flow and pressure capacity, as specified by the manufacturer, and their accuracy, as measured in a standardized fashion, were compared with directly measured pressure values. TYPE OF STUDY: Experimental study. METHODS: Two experiments were performed: (1) the achieved pressure was measured with the pressure sensor within a ball and compared with the preset pressure values. The pressure was increased constantly while the flow was kept constant. (2) maximum flow per minute was tested using a beaker and a stopwatch. RESULTS: The highest measured pressures for the Arthrex and the Stryker pumps were 115 mm Hg (46% of published maximum pressure) and 113 mm Hg (57% of published maximum pressure), respectively. The highest measured pressures for the Arthro FMS 4 and the InteliJet pumps were 251 mm Hg (101% of published pressure) and 132 mm Hg (88% of published maximum pressure), respectively. The maximal flow values for the Arthrex and Stryker pumps were 900 mL/min (56.3%) and 675 mL/min (48%), respectively. The Arthro FMS 4 and InteliJet pumps reached a maximal flow of 450 mL/min (56%) and 1,250 mL/min (62.5%). CONCLUSIONS: In the simpler pumps (Arthrex AR-6450 and Stryker 1.5L High Flow Pump), the pressure on the display must be set to higher values compared with the outflow-controlling pumps (Arthro FMS 4 and InteliJet) to achieve the same intra-articular pressure. All pumps were able to maintain a pressure of 60 mm Hg very accurately. Therefore, a surgeon can trust all of the pumps when the pressure is set below 60 mm Hg.

Preiser's disease: arthroscopic treatment of avascular necrosis of the scaphoid.

We report the case of a 50-year-old female patient with Preiser's disease (avascular necrosis of the scaphoid) who, after a 2-year history of wrist pain, underwent arthroscopic debridement of the necrotic scaphoid using a standard technique. Osteoarthritic changes of the articular cartilage, partial rupture of the scapholunate ligament, local synovitis, and loose fragments were documented. The patient reported significant improvement in pain relief and complete relief of mechanical symptoms at 31-month follow-up examination. Radiographs demonstrated no progression of collapse of the scaphoid or acceleration of degenerative changes in the wrist. Arthroscopy in Preiser's disease allows direct visualization and assessment of the exact pathology of the radiocarpal and midcarpal joint and the scaphoid cartilage. Arthroscopic debridement of the necrotic scaphoid increased wrist functional range of motion, provided excellent pain relief, and improved health-related quality of life.

A rare case of irreducible knee dislocation in a seventy-three-year-old male.

Knee dislocations usually can be treated by closed reduction, although a small number must be reduced surgically. A seventy-three-year-old patient sustained a knee dislocation while skiing, with entrapment of the medial capsule and the medial retinaculum in the femoral notch. There was no evidence of any vascular or nerve injury. Open reduction with transverse dissection of the medial retinaculum led to reduction. We achieved an excellent result by external fixation and early aggressive rehabilitation without repair of the avulsed cruciate ligaments.

[Microcirculation of striated muscle in closed soft tissue injury: effect on tissue perfusion, inflammatory cellular response and mechanisms of cryotherapy. A study in rat by means of laser Doppler flow-measurements and intravital microscopy]. / Die Mikrozirkulation der Skelettmuskulatur nach stumpfem Weichteiltrauma und Kryotherapie. Einfluss auf Gewebeperfusion und zelluläre Entzündungsreaktion.

The authors investigated the effects of closed soft tissue injury (CSTI) and cryotherapy on microvascular perfusion by means of laser Doppler flowmetry. In a different protocol interactions between leukocytes and the microvascular endothelium of skeletal muscle, which are first steps in local inflammatory response were documented in an intravital microscopy model. Rats were chronically instrumented with dorsal skinfold chambers. Leukocyte rolling and adherence in postcapillary venules of striated muscle before and after standardized muscle contusion (group T: n = 6), cryotherapy following muscle contusion (TK: n = 6) or sham contusion (group N: n = 6) were quantitated prospectively and in random order using intravital microscopy. Tissue perfusion was assessed by laser Doppler flowmetry in the microvasculature of the flap over a period of 96 hours following CSTI (group T: n = 8), cryotherapy following CSTI (group TK: n = 8), sham trauma (group N: n = 8, control 1), or cryotherapy following sham trauma (group K: n = 8, control 2). 300 minutes after trauma the number of rolling and adherent leukocytes in striated muscle microvasculature was significantly reduced by cryotherapy. We found an acute effect of cryotherapy on perfusion of traumatized tissue (reduction of perfusion around 25 %). However, there was no long-term effect (96 hours evaluation) on microvascular perfusion of cryotherapy either in the presence or absence of CSTI. The effectiveness of ice application in reducing edema in striated muscle following contusion may be due in part to a reduction of the leukocyte/endothelial interactions accompanying CSTI.

Implant failure of the gamma nail.

The gamma nail is a temporary implant characterised by a limited life expectancy under continuous dynamic stress. We reviewed a series of 839 patients with gamma nail stabilisation and found two fatigue fractures (0.2%) at the aperture of the distal locking holes. This complication has not been described in the literature. Metallurgic and scanning electron microscopic examinations proved that the fatigue zones occurred at the clover-leaf grooves, which is where the diameter of the gamma nail is reduced. The clover-leaf diameter is of no biomechanical use in gamma nail stabilisation. We suggested product modification of the gamma nail to produce implants with a round diameter instead of a clover-leaf shape. A modified implant is already in use at our institution.

Comparison of femoral and tibial pullout forces in bone-patellar tendon-bone anterior cruciate ligament reconstructions with a new interference fixation device.

Interference screws have become the standard method for fixing bone-patellar tendon-bone (BPTB) grafts. To avoid the inherent pitfalls and complications of interference screws, a 28-mm long and from 5 to 7 mm spreadable metal bolt with nontapping threads was developed for this study. The technical applicability and biomechanical characteristics of this new BPTB interference fixation device were investigated by dissection or tensile testing of 48 cadaveric knee specimens from young donors. No problems occurred with respect to bone plug anchoring during insertion of the spreading bolts. The clinically important linear load was 920+/-283 N for the femoral and 635+/-247 N for the tibial fixation site. Bone plug pullout was the mode of failure in all specimens. The results of this study indicate that the spreading bolt is a reasonable alternative to interference screws.

Arthroscopic resection of the radial head.

The authors describe arthroscopic radial head resection in patients with post-traumatic arthritis after fractures of the radial head or in patients with rheumatoid arthritis of the elbow joint, as an expanded indication for elbow arthroscopy. Arthroscopic radial head resection allows the surgeon to deal with the intrinsic joint pathology, as well as with accompanying symptoms such as synovitis, capsular contracture, or loose bodies. The portals used are the proximal medial, anterolateral, and the midlateral portal. The anterior three quarters of the radial head and 2 to 3 mm of the radial neck are resected with the stone-cutting abrader in the anterolateral portal and the arthroscope in the proximal medial portal. For resection of the posterior portion of the radial head, the abrader may be transferred to the midlateral portal. This permits resection of the remnants of the radial head posteriorly and also at the proximal radioulnar joint. Arthroscopic treatment allows the patient to begin and maintain an aggressive postoperative physical therapy program immediately after surgery, thus decreasing the risk of anterior scarring and reoccurring contracture of the capsule of the elbow joint.

Arthroscopic debridement for the treatment of Kienbock's disease.

The treatment results of seven patients (age range, 37 to 74 years, male:female ratio, 1:6) with Kienbock's disease (Lichtman stage IIIA-IIIB) who underwent arthroscopic debridement of the necrotic lunate bone and degenerative intrinsic ligaments were studied retrospectively. Osteoarthritic changes of the articular cartilage were documented in all cases. Partial (n = 2) and complete (n = 5) ruptures of the lunotriquetral and scapholunate ligaments, local synovitis (n = 5), and loose fragments (n = 6) occurred most commonly in the radiocarpal joint. All patients were available for an average of 19 months of follow-up (range, 6 to 42 months), physical examination, and radiographic evaluation. All patients reported significant improvement in pain relief and complete relief of mechanical symptoms. Radiographs showed progression of the disease in three cases; two of these were followed-up for more than 2 years. Arthroscopy in Kienbock's disease allows direct visualization and assessment of the exact pathology of the radiocarpal and midcarpal joint and the lunate cartilage. Arthroscopic debridement of the necrotic lunate increased wrist functional range of motion, provided excellent pain relief, and improved health-related quality of life in all patients.

Contusion of skeletal muscle increases leukocyte-endothelial cell interactions: an intravital-microscopy study in rats.

OBJECTIVE: To investigate the relationship between secondary muscle damage after contusion and the interactions between leukocytes and endothelial cells, which are essential steps in secondary inflammatory response. METHODS: In a randomized animal study, rats were chronically instrumented with dorsal skinfold microvascular chambers and exposed to standardized contusion or sham contusion. Leukocyte rolling and adherence in postcapillary venules before and after muscle contusion or sham contusion were quantitated using in vivo microscopy. RESULTS: The number of rolling leukocytes in the postcapillary venules before contusion was low. At 300 minutes after contusion, the number of rolling and adherent leukocytes in the striated muscle microvasculature was increased significantly (p < or = 0.05) compared with either the baseline precontusion condition or the control group at the same time. CONCLUSION: In the mid-term to long-term stages of skeletal muscle injury associated with contusion, a significant portion of tissue damage is secondary to leukocyte-endothelial cell interactions.

Femur fractures in patients with hip arthroplasty: indications for revision arthroplasty.

The number of periprosthetic femur fractures has increased due to the increase in the number of patients having total hip arthroplasty. In this study, we define indications for operative treatment in patients with femur fractures after hip arthroplasty. Fifty-three patients with 56 periprosthetic fractures were available for retrospective review of charts, radiographs, and physical examination; 42 fractures were treated with open reduction and internal fixation, 8 had replacement of hip prosthesis, 4 were treated with a retrograde genucephalic nail, and 2 patients were treated conservatively. The choice of treatment depended on the stability of the prosthesis and on the type and location of the fracture. Fifty-two fractures healed primarily. Three patients sustained a refracture, one an additional fracture, and two a deep infection. We recommend treatment with plate fixation for fractures without signs of prosthetic loosening. In fractures with loose implants, revision arthroplasty is required. Distal femoral fractures should be stabilized with a plate or with genucephalic nailing.