Background: During the past decades many treatments and devices were developed in attempt to unload the diseased articular surface in knee Osteoarthritis (OA). A novel biomechanical device and treatment methodology (The APOS System) was introduced in order to unload the diseased articular surface during activity (dynamic wedging), strengthen dynamic stabilizers and train neuromuscular control by means of controlled biomechanical perturbations. The purpose of this study is to examine the effectiveness of APOS System in reducing pain and improving function in knee OA patients.

Method: A double blind, randomized, prospective study was performed with 61 knee OA patients, aged 49–83 (66 ±8.1) years and graded 1–4 (3 ±1) according to Kellgren & Lawrence. Patients were randomized into research (active) and control (placebo) groups. All patients under-went 8 weeks of treatment. Patients were examined at baseline and supervised 4 times during the study. Patients in the research group used the biomechanical device that consists of 2 biomechanical elements located under the strategic weight bearing spots of each of the patient’s feet and a mounting and positioning mechanism embedded in designated shoes. The treatment methodology that was applied to the research group included dynamic wedging of the diseased articular surface. Patients in the control group used a placebo device without the biomechanical elements. Patients were assessed at baseline, after 4 weeks and after 8 weeks at the end of the study using Knee Society Score, WOMAC, SF-36, ALF and VAS. The assessment was performed without the examiner knowing the group affiliation of the patient.

Results: The two groups were statistically similar (p> 0.05) at baseline with respect to age, Kellgren& Lawrence classification and all assessed parameters including subscales. Significant difference between groups over time was observed for Knee Score (p< 0.001), Knee Society Function Score (p< 0.001), WOMAC (p< 0.001), SF-36 (p< 0.001), ALF (p< 0.001) and VAS (p< 0.001). Significant improvement was observed in the research group throughout all assessed parameters (measured improvement for Knee Score, Knee Society Function Score, WOMAC, SF-36, ALF and VAS were a multiplication of 1.8, 1.4, 3, 1.4, 1.35 and 2 in the applicable scale respectively). A slight deterioration was observed in the control group throughout all assessed parameters at final assessment.

Conclusion: The findings demonstrate that APOS System is effective and significantly improves function and reduces pain among knee OA patients.

Background: The embryology of the cruciate ligaments of the knee had received scant attention in the orthopaedic and embryologic literature. Understanding the embryonic development of the blood supply to criciate ligaments (CL) may help to comprehend the mechanisms of pathology leading to failure of these structures and of the revascularization process after reconstruction injured of cruciate ligaments or implantation of grafts.

Aim: To describe the anatomy and spatial relationships of the cruciate ligaments and their blood supply in the developing fetus.

Method: Knees from one leg of 48 normal human embryos from abortion material were examined, gestational age varying from early as the 8^th week and up to the 20^th week. Microscopic semi serial consequent sections of the knees were examined under light microscope and spatial changes within the cruciate ligaments were noted. The contra-lateral knees of some of the embryos were dissected to confirm the three dimensional picture. This gave us the possibility to follow the developmental changes of the spatial orientation of the cruciate ligaments and the blood vessels within them.

Results: The anterior and posterior cruciate ligaments are formed from a single mass of cells, divided by a sinovial septum. Folds within the septum partially divide the ligaments into bundles and carry within them the vasculature needed to sustain the ligaments. We show that the blood supply of the growing CL arises from the middle genicular artery and enters the ligaments from the poster-superiolateral corner (P.S.L.C.) of the inter-condylar notch, passes between the ACL and PCL and descends along he posterior aspect of the ACL.

These findings can explain why injury involving the P.S.L.C. in the adult has a worse prognosis for rehabilitation.

Introduction: Total hip arthroplasty preformed with the use of minimal incision surgery has received tremendous attention recently. Various surgical approaches have been introduced to minimize surgical trauma to the soft tissues. The mini invasive Modified Watson-Jones approach have been selected to decrease the perioperative complications associated with other mini invasive approaches that has been described.

The anterolateral mini incision is a new innovative approach using the intramuscular plan between the gluteus medius and the tensor fascia lata. This intermuscular interval through a small incision provides good exposure and preserves muscle integrity. Moreover, preserving the muscle integrity provides a very stable joint after implantation such that no restrictions is giving to the patient during the rehabilitation period.

Materials and Methods: Between July 2004 to September 2005, we used this approach on 60 sequential patients. Fifty patients were enrolled in this prospective study. Patients were evaluated preoperatively, immediately postoperatively, and at 3-month and 6 month follow-up according to operating time, intraoperative blood loss, subcutaneous drains blood loss, post op pain control drugs requirements, short form 36 patient questionnaire (SF-36) scores and the Harris Hip Score (HHS). 4 patients had previous THA on the contralteral side.

Results: The average operation time was 137min (range 90–200min), there were no dislocations, the mean post operation blood transfusion requirements was 1.64, the mean subcutaneous drains blood loss was 241.9ml (range 20–620ml), there was significant improvement in function, pain, SF-36 and Harris Hip Score (HHS) at the 3-month and 6-month follow-up examination. The average length of the incision was under 12cm. We had one reoperation due to deep infection. All four patients with bilateral THA preferred their last operation due to lack of post operative restrictions and due to shorter recovery of muscle strength.

Conclusion: We think that using mini invasive Modified Watson-Jones approach in total hip replacement surgeries is a preferable option. There are several advantages of using this approach compared with the more traditional techniques. Such a technique should help reduce morbidity and complication rates for those patients undergoing a total hip replacement.

Aim: To evaluate the long term effect of Distal transfer of the greater trochanter in Perthes’ disease.

Patients and methods: Twelve patients (thirteen hip joints, 10 males and 2 females) who suffered from Perthes’ Disease were treated by distal transfer of the greater trochanter (DTT). The operation was performed because of progressive shortening of the articulo-trochanteric distance accompanied by signs of insufficiency of the hip abductors. Total or near total femoral head involvement was found in all the patients except for one of them. Follow up period was 28 years (21–35). Mean age at diagnosis of Perthes’ was 7 years (4–11). Patient were studied in 1992 and reviewed again 13 years later, using the Harris hip score, short form 36 (SF36), physical examination and A-P X-rays.

Results: Not one of the patients underwent a total hip arthroplasty. Mean Harris hip score is 80 (range 54–100, 4 patients under 70 score). Mean SF36 score was 71 (range 30–94) and was correlated to the Harris score. Three of the patients were working in a physically demanding profession. The rest were office workers. Two of them chose non strenuous type of work due to the hip condition. Limb length discrepancy was 1.7 cm short on the operated side (range 0–3) and correlated with Trendelenburg sign (4 patients with positive sign). Femoral head sphericity according to Stulberg classification was good in 5 patients (grades 1–2), fair in 3 patients (grade 3) and poor in 4 patients (grade 4–5). Head sphericity was not correlated to age at diagnosis, Harris score, SF36 score or level of hip pain.

Conclusions: Long term outcome are surprisingly good in those patients, considering the degree of head involvement, advanced age at diagnosis and severity of disease which necessitated high degree of varus osteotomy and hence trochanter transfer.

Introduction: MRI of the knee is routinely performed in supine position, without providing information about physiological weight bearing. Since erect knee MRIs can be performed in a double-donut MRI, we sought to compare supine and weight bearing knee MRIs of patients with and without osteoarthritis (OA).

Materials and Methods: On a 0.5T double-donut open MR 16 patients were studied in supine and erect: 10 with OA and 6 age matched asymptomatic patients.

The joint space, coronal and sagittal meniscal thickness, extrusion in 4 directions, meniscal angles, intermeniscal space and evaluation of menisci, ligaments and marrow were compared between positions in the OA and control groups. Correlation with medial knee pain was obtained.

Results: The average intermeniscal space was greater in OA and in the erect position. The joint space was narrower in OA especially in the medial compartment and in the supine position (p< 0.02). The mean meniscal thickness was similar in both positions and groups.

In OA the meniscal angle was larger when upright, without statistical significance.

The medial, lateral and anterior meniscal extrusion were greater in OA on vertical and supine, especially the anterior extrusion of medial meniscus which was significantly higher in OA (p= 0.0259, 0.0122, vertical, supine, respectively( and on vertical position (p= 0.0041).

Medial extrusion was higher in OA on both positions (p= 0.0228, 0.0184 vertical , supine).

Medial meniscal tears were seen in 6/10 OA and 2/6 controls. MCL grade 1 sprain pattern was seen in 4/10 OA, chronic ACL tear was seen in 5, and subchondral marrow edema in 8/10.

7/10 OA patients complained of knee pain which was predominantly medial.

Conclusions: Standing MRI shows relative widening of the joint, possibly due to the altered osseous alignment. Extrusion of the meniscus and intermeniscal space are more common in OA and under weight bearing. Medial meniscal extrusion correltaes with osteoarthritis and worsens under weight bearing. This may explain the common medial knee pain in osteoarthritis as seen in data from the orthopedic literature, as well as the clinical evaluation of our patients, and may be attributed to increased pressure on the capsule or MCL.

Osteoarthritis (OA) is associated with biochemical and mechanical processes that release different wear particles into the synovial fluid. Unfortunately, symptoms such as pain, swelling and limited range of motion often do not correlate with the level of OA as observed by X-ray. In addition, the mechanisms of OA and the processes involved are still not clearly understood. Therefore, there is much interest in developing new diagnostic techniques that would provide means to both sensitive, objective determination of joint damage and studying the underlying mechanisms. Such a technique may also aid in evaluating the efficiency of drugs under development objectively and relatively quickly.

Bio-ferrography (BF) is a method for magnetic isolation of target cells or particles in a fluid. The current project was aimed at evaluating the applicability of BF for isolation and analysis of specific wear particles in human joints. Synovial fluid aspirates were drawn during either arthroscopy or total joint replacement from 14 patients with either OA or other types of chondropathy. Target components of bone and cartilage (collagen type I and type II, respectively) were labeled with monoclonal antibodies coupled to magnetic beads. The captured particles were isolated on microscope slides by means of BF and characterized by several optical and scanning electron microscopy techniques combined with chemical analysis. The number, size and shape of particles were quantified by image analysis.

Results showed that specific labeling of target collagens enables capture of a much higher number of particles in comparison to previous reports. A variety of particles with different morphologies and sizes were documented. The number of captured particles changed in different patients. In addition to bone and cartilage fragments, particles of repaired cartilage that contained collagen I, meniscus particles containing collagens I and II, and magnesium-rich particles that could form during biochemical dissolution of hydroxyapatite or precipitation from body fluids, were identified. Further in-depth characterization of these particles would shade more light on the mechanisms and processes involved in joint degradation. The evaluation of joint damage by BF was found to correlate with clinical observations.

It was concluded that BF has the potential of becoming a powerful tool in the study of human joint diseases. Future studies may use even more specific labeling of joint components. BF may become a routine diagnostic technique, aiding the orthopedist in determination of OA level in an objective manner. The ability to draw samples quickly during arthroscopy with little discomfort to the patient could facilitate routine serial assessment of particular joints.

Objective: To evaluate viscosupplementation by intraarticular injection of Orthovisc® Vs. Synvisc® (Molecular Weight 1.55 and 6 Million Daltons, respectively) in the treatment of knee osteoarthritis in clinical practice in Israel.

Methods: We performed a prospective evaluation of all patients treated with either Orthovisc® or Synvisc® by the senior author during a 2 year period. All patients suitable for hyaluronic acid injections were included in the study. Patients bought either product at their own expense and preference.

A total of 1566 injections were performed involving 522 knees. Patients were divided into two groups; one consisting of 277 patients who purchased Orthovisc® and a second consisting of 245 patients who purchased Synvisc®.

A Visual Analog Scale (VAS) assessed pain. The senior author performed all injections and sterile injection protocol was strictly adhered to.

Knees were injected at weekly intervals for 3 weeks. Patients were assessed at baseline, 1, 2, 3 & 4 weeks and 3, 6 & 12 months following initial visit.

Results: Both products were found to be of clinical benefit and have an acceptable safety profile. No difference in VAS values was found between the two groups. The calculated Power of Study for detection of a one-pain unit difference was 99.9% (α=0.05). This power was maintained through the first three visits and later declined.

Conclusion Our findings question the impact of hyaluronic acid molecular weight in alleviating osteoarthritic knee pain.

Bio-ferrography (BF) is a method for magnetic isolation of particles suspended in liquid on a glass slide. The objective of the current research was to evaluate the potential use of BF in determining the wear level of artificial hip and knee joints based on analysis of aspirated synovial fluids.

Synovial fluid aspirates and prosthesis compartments removed by revision surgery from 14 patients were analyzed. The synovial fluid was centrifuged to separate the wear particles from the hyaluronic acid. The failed prostheses were washed in the lab with either saline or distilled water to remove and capture unbound wear particles. An erbium chloride (ErCl₃) solution was added in some cases to induce increased magnetization. The wear particles were isolated by means of a Bio-Ferrograph 2100 system, and characterized by means of several optical and scanning electron microscopy techniques as well as energy dispersive spectroscopy. The number and size of particles were quantified by image analysis. The failed prostheses were also characterized in order to determine whether BF can monitor the wear of artificial joints.

Results showed that metallic (namely, Ti-, Co- and Fe-based alloys), polymeric (namely, UHMWPE, POM and PMMA) and bone particles could be isolated on slides by BF. The isolated particles exhibited a variety of shapes and surface morphologies that were dependent on the process by which they had been formed. No other technique allows retrieval and isolation of so many tiny particles, either metallic or non-metallic, while preserving their shape for microscopic examination and chemical analysis. A correlation existed between the level of prosthesis degradation, as inspected during failure analysis, and the number and size of isolated particles; namely, an increase in number and size of particles represented increased prosthesis wear. When the prosthesis was visually in good condition, very few small particles were retrieved from the synovial fluid. The formation of metal and bone particles in several cases accelerated further wear of these prostheses.

On the basis of the good correlation between the classification of damage by BF and the level of artificial joint degradation as evaluated during failure analysis, it was concluded that BF of synovial fluids may be used in the study of artificial joints failure. In addition to monitoring the level of wear, it allows determination of the mechanism and cause of failure, thus providing feedback on problems associated with design, manufacturing and installation of artificial joints. The ability to draw samples quickly during joint aspiration with little discomfort to the patient could facilitate periodic ferrographic evaluation of specific joints. Such information may also prove invaluable in the design of improved prostheses. In these cases, the atlas of wear particles that was constructed in this project for the first time may be used as a reference.

Study design: In order to evaluate a new CECT (Continuous Enhanced Circulation Therapy) based on protocol for DVT prevention a prospective, randomize, single-blind study was designed to compare the effect of the new protocol to the current standard of care in DCT prophylaxis (LMWH).

Objectives: To evaluate and compare the incidence and severity of DVT between the two groups.

Background: Total hip and knee replacements are operations particularly prone to thromboembolic complications. Recommendations regarding prophylaxis have changed over the years. A treatment protocol was proposed, based upon the CECT system as the primary DVT prophylaxis method with the addition of low dose aspirin. This protocol is using two very safe treatment modalities with very low risk for adverse effects. The CECT system applies continuous mechanical enhancement of venous blood flow through a miniature, mobile, battery operated system.

Methods: 39 patients, who underwent total hip or knee replacement, were prospectively randomized into two groups. In the study group the patients received CECT system starting immediately after the induction of anesthesia and covering the operation and the first 5 postoperative days, within 12 hours after surgery aspirin 100 mg per day was added. In the control group the patients received Enoxaparin 40 mg per day for 5 postoperative days. A venography was performed at the 5th to 8th post-operative day and the DVT prevalence was compared.

Results: In the study group 3 patients out of 21 (14.3%) were found to have DVT (1 of them proximal), compared to 8 patients out of 18 (44.4%) in the control group (5 of them proximal). The differences between the two groups are statistically significant for both total and proximal DVT rates (p=0.037).

In the study group only 1 patient needed prolonged high dose anticoagulant treatment while 6 patients in the enoxaparin group were treated (p=0.020).

The cumulative incidence of adverse events in the study group was significantly lower than that observed in the control group (p=0.000). Average postoperative hospital stay was 8.4 days in the study group and 11.7 days in the control group (p=0.002).

The CECT device was very well tolerated by the patients and facilitated early mobilization.

Conclusions: The protocol combining CECT and Aspirin was found to be both safe the effective. Comparison to the standard prophylaxis with enoxaparin revealed significant advantage of the proposed protocol with: better DVT prevention, less adverse events and shorter hospital stay. Further research is needed in order to establish the place of this prophylaxis protocol as the treatment of choice in orthopaedic patients.

Objectives: Assessment of the need for bolt removal in long stem distally interlocked revision stems.

Introduction: Proximal stress shielding might prove in the long run detrimental to the success of distally fixed revision stems. In our department during the last 4 years a proximally fixed stem combined with distal interlocking has been used. The manufacturer recommends bolt removal 18 months after surgery. The current investigation was conducted in order to assess the need for bolt removal.

Methods: 22 consecutive stems inserted from 1997 to the present were included. In all these cases femoral bone loss was graded according to Paprosky. A locked long stem is indicated in bony deficiencies of Grade 2B, 2C or 3 (i.e. loss of at least the metaphysis shell with or without major diaphyseal bone loss). Volkmann’s trans-femoral approach was used in 19 cases and sliding trochanteric osteotomy in the rest. Impaction grafting or structural allografts were not used to stabilize the prosthesis. In all cases grade II fixation (according to D’Antonio) was achieved at the end of the procedure.

Results: Median follow-up is 14 months. There were no septic complications. In two cases bolts slippage allowed prosthesis subsidence. One stem had to be revised due to aseptic failure. During surgery the prosthesis was markedly smaller than the regenerated medullary canal, and proximal bony fixation was not achieved. One patient’s bolts broke and in another case screw migration into soft tissue occurred. All patients attained ambulatory status. In none of the patients were the screws removed.

Discussion: Our results seem not to support the manufacturer’s recommendation for elective screw removal. Osteotomy healing appears to occur in all cases, however, time to healing varies greatly. The range of complete healing is from 3 months to 24 months. It does not appear that bolt retention leads to an interference with bone healing and bone regeneration of the proximal femur at the osteotomy site. Bolt breakage is rare and does not appear to adversely affect the results at least in the short term.

Study Design: Thirty-four patients who were operated for spinal deformities with the Spine System Evolution (SSE) were retrospectively reviewed.

Objectives: To evaluate the efficiency of SSE to correct spinal deformities.

Summary of Background Data: Since the end of the Harrington rods era, several instrumentation were introduced for correction of spinal deformities. Most of these instrumentations are evolution of he CD instrumentation and are based on combination of translation, distraction/compression and possible some rotation forces. Cord injuries were informed to be more frequent with the new instruments and are related both to ischemic injuries and to mechanical insults to the cord by the supralaminar and the infralaminar hooks. Correction by the SSE is based on pedicle screws and pedicular-transverse locks. No hook is inserted into the spinal canal.

Methods: All charts, radiographs, and images of the patients operated for spinal deformities with the SSE were reviewed. Thirty-four patients were found. For the purpose of this study they were evaluated for the amount of correction achieved, balance of the spine, subjective satisfaction of the cosmetic appearance and the surgical complications.

Results: The mean age of the operated patients was 19.5 years. Twenty-one were operated for idiopathic scoliosis and were found to have 61% correction of the major curves. Five patients were operated for neuromuscular scoliosis with 69% of correction in average, four were operated for thoracic hyperkyphosis with reduction of the curves to physiologic range in all of them and four were operated for adult scoliosis with 38% of correction. Twenty-eight patients were satisfied from the results and the same number of patients were found to be balanced in the range of up to one-centimeter shift from the mid-line. No patient was found to have any major neurologic complication and no deep wound infections was registered. One patient had postoperative bronchopneumonia, another one had pneumothorax, one had superficial wound infection and another girl was troubled with her body image.

Conclusions: SSE instrumentation was found friendly to use and relatively safe for correction of spinal deformities.

Methods of study: Prospective Controlled Animal Study.

Objectives: Evaluation of the feasibility of embryonal epiphyses transplantation in a xenogeneic model for reconstruction of adult articular cartilage in a rabbit model.

Introduction: Articular cartilage reconstruction has been the goal for many years of orthopaedic research. Current acceptable techniques include the use of allografts, autologous chondrocytes transplantation and osteochondral cylinder grafting. Reconstruction of articular cartilage defects using adult osteochondral allografts is an established clinical procedure, whose principal drawback is lack of lateral integration of the grafts to the surrounding tissue. Autologous chondrocytes transplantation is a sophisticated technique requiring cell culture and a staged operation. Its main draw back is the lack of mechanical strength early on and the prolonged rehabilitation period. This study was conducted in order to evaluate the possibility of using embryonal epiphyses as a cartilage reconstruction tissue.

Methods: A xenogeneic human to rabbit sub-acute osteochondral defect model was designed to evaluate the possibility of allogeneic implantation in humans. The following procedures were performed (n=5): transplantation of: 1. live epiphyses, 2. live epiphyses with autogeneic periosteum, 3. devitalized epiphyses, and 4. devitalized epiphyses with autogeneic articular chondrocytes.

A fifth control group did not receive any implant. Animals were followed for 3 months after transplantation and than sacrificed. The histological specimens were evaluated by image analysis after immuno-histochemical stains were performed (including the following antigens – collagen type II, collagen type I, collagen type III, collagen type X, S-100, alkaline phosphatase, osteocalcin, osteopontin, nitric oxide synthase).

Results: Animals in groups 1 and 2 had a viable reconstruction of the articular surface with little evidence of rejection and without pannus formation. Animals in groups 3 and 4 became severely arthrotic and the graft was resorbed. Nitric oxide synthase accumulation was reduced in group 1 and 2 as compared to groups 3, 4, and 5, indicating a joint preserving function of the epiphyseal grafts.

Discussion: Epiphyseal grafts appear to be a feasible procedure for reconstruction of articular cartilage defects even in a xenogeneic model. The restoration of articular cartilage even with a xenogeneic graft appears to prevent nitric oxide synthesis and the resulting destruction of unafflicted articular cartilage. This is a major pathway leading to secondary osteoarthritis after joint injury. Blocking this pathway might prevent degenerative changes.

Disruption of the major ligaments of the knee was seen in six young men, five parachutists and a house painter, after what we have termed abduction-traction injury. This unusual complaint results from the application of a sudden block to the ankle while falling head first, leading to traction and abduction of the knee. All the patients underwent operations, generally with unsatisfactory results. At operation tears of the anterior cruciate ligament, medial collateral ligament and posterior oblique ligament were seen in each case; in four patients the posterior capsule and in three the posterior cruciate ligament also were torn. In one patient the lateral collateral ligament was torn and the lateral meniscotibial ligament was avulsed. The compression component is absent in this type of injury and consequently the menisci and the osteochondral surfaces of the tibia and femur remained intact in each case.