Is the human acetabulofemoral joint spherical?

The human acetabulofemoral joint is commonly modelled as a pure ball-and-socket joint, but there has been no quantitative assessment of this assumption in the literature. Our aim was to test the limits and validity of this hypothesis. We performed experiments on four adult cadavers. Cortical pins, each equipped with a marker cluster, were implanted in the pelvis and the femur. Movements were recorded using stereophotogrammetry while an operator rotated the cadaver's acetabulofemoral joint, exploiting the widest possible range of movement. The functional consistency of the acetabulofemoral joint as a pure spherical joint was assessed by comparing the magnitude of the translations of the hip joint centre as obtained on cadavers, with the centre of rotation of two metal segments linked through a perfectly spherical hinge. The results showed that the radii of the spheres containing 95% of the positions of the estimated centres of rotation were separated by less than 1 mm for both the acetabulofemoral joint and the mechanical spherical hinge. Therefore, the acetabulofemoral joint can be modelled as a spherical joint within the considered range of movement (flexion/extension 20 degrees to 70 degrees ; abduction/adduction 0 degrees to 45 degrees ; internal/external rotation 0 degrees to 30 degrees ).

C-reactive protein and erythrocyte sedimentation rate changes following arthroscopically assisted anterior cruciate ligament reconstruction.

We studied changes in C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) to establish normal values after uncomplicated anterior cruciate ligament (ACL) reconstruction. The levels of CRP and ESR were determined by serial measurements in 45 consecutively treated patients. Blood samples were collected before surgery and on postoperative days 1, 3, 7, 15, and 30. Both ESR and CRP showed a marked increase postoperatively, peaking between the 3rd and 7th postoperative days, the latter showing a faster return to normal ( P=0.286). These data show that CRP can be used as a more accurate predictor than ESR of postoperative complications if the blood level remains elevated or unexpectedly rises.

One-stage arthroscopically assisted anterior and posterior cruciate ligament reconstruction.

PURPOSE: To retrospectively evaluate 15 consecutive patients who underwent simultaneous isolated, arthroscopically assisted anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) reconstruction. TYPE OF STUDY: Case series. METHODS: A bone-patellar tendon-bone autograft was used as the PCL substitute and doubled hamstring tendons were used as the ACL graft. The IKDC evaluation form and the HSS, Lysholm, and Tegner clinical rating scales were used to make clinical evaluations. Anteroposterior translation was measured with the KT-2000 arthrometer and stress view radiography. RESULTS: At final IKDC evaluation, 3 patients (20%) were graded A, 7 (46.7%) were graded B, 3 (20%) were graded C, and 1 patient (6.7%) was graded D. One patient underwent revision surgery in another hospital for severe postoperative residual laxity. Two C-graded patients had an unsatisfactory outcome as a result of serious complications related to knee injuries. All patients with a grade A or B returned to sports activity. At stress view examination, mean posterior side-to-side translation measured at the lateral tibial plateau was 5.8 +/- 1.1 mm and the mean translation at the medial tibial plateau was 7.3 +/- 1.5 mm; the mean anterior dislocation was 3.3 +/- 0.4 mm. The preoperative HSS score rated an average of 32 +/- 9. Postoperatively, the average score reached was 89.6 +/- 8.3. The preoperative Lysholm score was 65.5 +/- 9.1 (range, 48 to 78) in patients with chronic lesions and at follow-up was 95.1 +/- 4.5 (range, 88 to 100). The average Tegner activity score decreased in patients with chronic lesions from 6.9 +/- 1.7 (range, 4 to 9) before injury to 5.5 +/- 1.6 (range, 2 to 9) at follow-up (P =.053 ). At follow-up, 7 patients (50%) returned to their preinjury level after surgery. CONCLUSIONS: These results show the effectiveness and safety of simultaneous arthroscopic reconstruction of both cruciate ligaments using autografts that can adequately restore satisfactory stability, even in the presence of minimal peripheral laxity (1 degrees or 2 degrees ). We conclude that the use of autografts can restore ligament function with good patient compliance and without significant surgical complications.

Transcondylar screw fixation in anterior cruciate ligament reconstruction.

PURPOSE: The purpose of this study was to investigate the outcomes of 2 different methods of femoral fixation for arthroscopically assisted anterior cruciate ligament (ACL) reconstruction. TYPE OF STUDY: Double-blind prospective study. METHODS: Fifty-five patients were prospectively evaluated at 2-year follow-up. In group A, 24 patients underwent arthroscopic ACL reconstruction with bone-patellar tendon-bone and interference screw fixation. In group B, 31 patients underwent arthroscopic ACL reconstruction with bone-patellar tendon-bone and transcondylar screw fixation. Patients were evaluated by using the IKDC form, Lysholm-II form, Tegner scoring system, and KT-2000 arthrometer. RESULTS: In group A, final IKDC clinical evaluation achieved 0% grade A, 62.5% grade B, 25% grade C, and 12.5% grade D. In group B, 29.1% achieved grade A, 54.8% grade B, 12.9% grade C, and 3.2% grade D. The difference was statistically significant (P <.05). The injured versus normal side-to-side KT-2000 difference at maximum manual loading was 3.68 mm (SD, 1.71) in group A and 1.64 (SD, 2.05) in group B (P <.0001). CONCLUSIONS: This prospective study could not provide significant data suggesting that 1 method of fixation is superior to the other. Therefore, we consider both methods comparable in terms of stability and functional outcome at short-term follow-up. Transcondylar fixation offers the following advantages: fixation without intra-articular hardware, greater bone-to-bone fixation, and the possibility of fixation with breakage of the posterior femoral tunnel wall. Moreover, this method may be a useful alternative in revision ACL surgery.

Postoperative bleeding following notchplasty in anterior cruciate ligament reconstruction: thermal radio frequency versus powered instrumentation.

This study compared postoperative bleeding during anterior cruciate ligament (ACL) reconstruction following notchplasty by power instrumentation with that following radiofrequency. Between January 1998 and April 1998 we prospectively divided 24 consecutive patients undergoing arthroscopic ACL reconstruction with bone-patellar tendon-bone autograft into two groups. Notchplasty was performed by powered instrumentation in group A (n=12) and by radiofrequency in group B (n=12). Two Redi-Vac suction drains were placed, one intra-articularly and the other subcutaneously at the harvest site and tibial tunnel. All drains were removed 48 h postoperatively. The first drainage measurement (end of surgery, 6 a.m. postoperative day 1) showed average total bleeding of 124.16 cc in group A and 65.41 cc in group B (P<0.001); per hour this was 10.21 cc in group A and 5.49 cc in group B (P<0.001). The second drainage measurement (6 a.m. postoperative day 2) showed average total bleeding of 44.55 cc in group A and 17.78 cc in group B (P<0.01); per hour this was 1.85 cc in group A and 0.74 cc in group B (P<0.001). Radiofrequency technology can be used when performing intercondylar notchplasty in ACL reconstruction. As a result of this technique postoperative intra-articular bleeding was significantly reduced.

Postoperative physiopathological analysis of inflammatory parameters in patients undergoing hip or knee arthroplasty.

Infection after total hip or knee arthroplasty is a major concern for the orthopedic surgeon. Because postoperative recovery in patients undergoing hip or knee replacement is always characterized by a shift in basal laboratory parameters, the value of the routine use of these parameters in the detection of this major complication is controversial. The aim of this study was to evaluate the physiological behavior of these parameters, the most reliable of which are C-reactive protein (CRP), erythrocyte sedimentation rate (ESR) and white blood cell count (WBC). The pattern of these parameters was observed for 60 days after surgery in 74 patients (48 males and 26 females) who underwent total hip or total knee arthroplasty. Mean age was 65.4 years. ESR reached a peak on day 5 and then decreased as much as 3-fold by day 60. CRP displayed even greater sensitivity with a peak level on day 3 followed by a rapid return to basal levels. WBC also peaked on day 1. No significant differences were found between total hip arthroplasty and total knee arthroplasty. Observation of the pattern of these parameters identifies any nonphysiological modifications and enables suitable measures to be adopted.

Current concepts in diagnosis and treatment of posterior cruciate ligament injury.

Injuries to the posterior cruciate ligament (PCL) have traditionally been reported to be rare but in the last decade, this ligament has captured the attention of orthopaedic surgeons world-wide. While new or improved surgical techniques involving the PCL have achieved attractive results, accurate evaluation of the PCL-deficient knee still remains a challenge. Despite the greater use of new, more sensitive clinical testing, stress radiography and MRI, correct diagnosis and staging of the PCL tear is still difficult. The objective of this paper is to provide an up-to-date review regarding diagnosis and treatment of the PCL tear.

A mould arthroplasty revision: a 43-year follow-up.

We present the outcome of a mould arthroplasty implanted for a congenital hip dysplasia in 1955 to revise a previous cup arthroplasty. This type of prosthesis, which has been developed on the basis of the concept of Smith-Peterson, by Prof. Marino-Zuco in Rome in the early 1940s, showed excellent results and was widely used until the advent of Charnley low-friction arthroplasty.

The efficacy of arthroscopy in the treatment of hip osteoarthritis.

We evaluated the utility and the safety of arthroscopy for diagnosing and treating symptoms in patients with osteoarthritis (OA) of the hip. We studied 133 patients consecutively treated for hip OA, using a modified Harris Hip Score (HHS) for the clinical assessment: There were no related complications or infections. At an average follow-up of 18 months, 61% of patients showed an improvement of their preoperative score, although only 36% of those actually presented good or excellent results. The remaining 39% of the total, either developed recurrent symptoms or underwent a major surgical procedure after arthroscopy. Benefit derived from the arthroscopy procedure depends strictly on either age or OA severity. Arthroscopy of the hip joint is a safe tool for managing problems related to OA of the hip. Careful selection of patients must be performed to identify those who will benefit most from the procedure. It seems that young patients with early OA are those associated with a higher rate of procedure success.

[Synovial healing in reconstructed cruciate ligaments. Our personal experience compared in single interventions and combined reconstructions]. / La maturazione sinoviale dei legamenti crociati ricostruiti. Esperienza personale a confronto negli interventi isolati e nelle ricostruzioni combinate.

INTRODUCTION: The healing process of tendon grafts used in cruciate ligament reconstruction is called ligamentization. The tendon structural architecture changes progressively into the histological appearance of normal ligament. Amiel and Clancy have demonstrated that this process is time-dependent in anterior cruciate ligament (ACL) reconstruction, the tendon graft taking one year to become similar to a normal cruciate ligament. Three different maturation phases of anterior cruciate graft ligamentization can be seen at MRI: periligamentous proliferation, intraligamentous proliferation and definitive healing. We report our MR findings in the reconstruction of single ACL, posterior cruciate ligament (PCL), and of both ACL and PCL. MATERIAL AND METHODS: January 1995 to January 1999 we selected 60 patients submitted to arthroscopic cruciate ligament reconstruction. The ACL was reconstructed with the patellar tendon in 22 cases and the PCL in 23; fifteen patients underwent double reconstruction of ACL, with hamstring tendons, and PCL, with patellar tendons. Fifty-five patients were followed-up with MRI: 45 with a dedicated permanent magnet (Artroscan, Esaote Biomedica, Genoa, Italy) and 10 with a permanent low-field unit (AIRIS, Hitachi, Japan); the same technical parameters were used in all cases. Forty of 55 patients were examined at 1, 3, 6, 9 and 12 postoperative months, while 15 were followed-up longer (12 to 36 months postoperatively). At the first follow-up MR examination, 5 patients (2 ACL and 3 PCL) were excluded for incorrect tunnel position (1 case), hypertrophic scarring (2 cases) and new trauma (2 cases). MR findings were compared with clinical data of joint stability. RESULTS: MRI showed the different stages of the healing process in 20 ACL patients: proliferating soft tissue around the graft with the low signal intensity typical of tendons (stage I, 1-3 months postoperatively), the graft becomes progressively hyperintense (stage II, 3-9 months postoperatively), and finally the low signal intensity indicating completed ligamentization (stage III, 12 months postoperatively). As for PCL reconstructions, MR findings were similar but the process took longer, even 24 months. Finally, in the 15 cases of double reconstruction, both grafts were difficult to distinguish on T1-weighted images for a very long time (24-36 months postoperatively). DISCUSSION AND CONCLUSIONS: Relative to the ACL, ligamentization takes longer for PCL and combined ACL and PCL reconstructions, probably because the morphological changes in PCL and double grafts may be impaired by many factors, such as gravity, long bone tunnels, hemarthrosis, hyperplastic synovial reaction in the intercondylar notch; also, rehabilitation protocols differ in ACL from PCL patients. No signs of instability were found at physical or arthrometric examinations. MRI demonstrates the different stages of ligamentization and thus proves a useful tool for postoperative follow-up in cruciate ligament reconstructions. Contrast-enhanced (Gd) studies are reserved to the cases of graft impingement or if other abnormalities are suspected.

Intra-articular lipoma of the hip. A case report.

This report describes a rare intra-articular lipoma of the hip which developed in a 31-year-old male after a football injury. A plain X-ray and an MRI scan of the hip showed no bony abnormalities. After the patient failed to improve with a rehabilitation programme, arthroscopy of the hip was performed, revealing a lump in the acetabular fossa associated with a labral tear. A histopathological analysis confirmed the diagnosis of an intra-articular lipoma of the hip joint, which to our knowledge is the first reported case in the literature.

Markers of connective tissue activation in aseptic hip prosthetic loosening.

The fundamental role played by macrophages and fibroblasts of the synovial-like membrane in aseptic hip prosthesis loosening (AHPL) has recently been confirmed by numerous studies. In this study, the activity of these cells in patients with prosthetic loosening was analyzed by evaluating the main markers of fibroblast and macrophage activation in sera and in supernatants of cultured fibroblasts obtained from AHPL patients who underwent revision of a loose total hip arthroplasty implant. In these patients interleukin-1, hyaluronic acid (HA), and type III procollagen peptide were evaluated. The results were compared with those obtained in 13 patients with firmly fixed implants and 13 patients with osteoarthritis. Serum HA levels were significantly higher (779.3 +/- 951.6 micrograms/L) in patients with AHPL as compared with patients with firmly fixed implants (112.9 +/- 84.9 micrograms/L) and osteoarthritis (115.3 +/- 107.8 micrograms/L). Type III procollagen peptide levels were elevated in only 33.3% of patients with AHPL, whereas interleukin-1-beta (IL-1 beta) was detectable in 4 patients with AHPL but not in patients with firmly fixed implants or osteoarthritis. In supernatants, IL-1 beta was measurable in 4 of 6 fibroblast cultures, whereas type III procollagen peptide and HA were measurable in all cultures. The data confirm the existence of an inflammatory process in AHPL patients in which macrophages and fibroblasts play a key role. The detection, in these patients, of high circulating levels of IL-1 beta and HA is very important from a clinical point of view because they could be considered specific markers of inflammation.

Relationship between osteoarthrosis and osteoporosis. An experimental and clinical study.

The authors conducted two studies to demonstrate the presence of a relationship between osteoporosis and arthrosis: the first study was experimental involving thirty femoral heads removed during hip arthroplasty, and the second was a clinical study conducted on forty patients with coxarthrosis. The results obtained confirm how the presence of one of the two pathologies may prevent or delay occurrence of the other, and on this basis the authors review the literature. Finally, also taking into account the interpretations of other authors, possible hypotheses on the inverse relationship that links the two pathologies are proposed.