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Orthopaedic Proceedings
Vol. 92-B, Issue SUPP_I | Pages 107 - 108
1 Mar 2010
Randelli F D’Anna A Randelli P Visentin O Arrigoni P Randelli G
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Dislocation is the most relevant early complication after primary total hip replacement (THR) in literature. Many factors have been advocated for dislocation, either surgeon-related either patient-related. Component positioning seems to be of major importance in determining dislocation. We evaluated 152 randomised THR with a CT study between 985 THR done at our Institute since november 2004 to november 2006.

152 randomised primary THR on a total of 985. The same prosthetic pattern (head size, stem, cup). Lateral approach with total capsulectomy and external rotator tendon resection. All 152 patients underwent a post operative standardized CT study assessing cup antiverion and inclination angles and stem antiversion angle. Dislocated patients where furthermore analysed for any detail concerning their procedure and follow-up. A safe zone was then deduced for safer positioning.

During the follow-up period dislocation occurred in 5 hips (only one in the randomised group) assessing our rate of dislocation at 0.5%. All dislocation were managed with closed reduction and an articulated hip brace. No open reduction or revision surgery were further needed. The mean cup abduction was 47° in the dislocated hips and 49° in the control group. Mean cup anteversion was 29° in both groups. The mean stem anteversion was 8.2° in the dislocated group and 3.1° in the control group. No statistical difference could be reached between dislocation and cup positioning. A correlation between hip dyspalsia (Crowe II) as primitive diagnosis and dislocation could be reached considering all the THR procedures.

In THR inappropriate cup and stem positioning is considered an important risk factor of postoperative dislocation. Accurate and reproducible measurement is mandatory for implant positioning evaluation. Conventional radiographs cannot provide accurate and reproducible measurement. CT can provide a precise measurement of prosthetic components. Several studies failed to demonstrate a correlation between component positioning and dislocation often because of small number of patients and many bias. We tried to reduce bias using the same prosthetic pattern and the same surgical approach. Notwithstanding we could not reach a statistical difference in term of prosthetic positioning between dislocated and control group. Perhaps the dislocated group was too small to have a statistical meaning. We could determine a Safe Zone of cup and stem positioning for our patients: cup anteversion between 24° and 33°, cup inclination between 42° and 50°, stem anteversion between −3° and 10°.

Dislocation is the main early complication after THR. Its etiology depends on many factors. Sometimes the cause can’t be identified. Orientation of prosthetic components may be responsable for dislocation but its truly correlation can be hard to be assessed. In this study we found no correlation between implant positioning and occurrence of dislocation, but we defined a tighter Safe Zone than previous reported, in which the risk of dislocation is nought. A correlation between hip dyspalsia (Crowe II) as primitive diagnosis and dislocation could be reached.


Orthopaedic Proceedings
Vol. 92-B, Issue SUPP_I | Pages 94 - 95
1 Mar 2010
Randelli F Randelli P Visentin O Arrigoni P Randelli G
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Metal on Metal coupling in total hip replacement has been widely used since many years. After the rebirth of resurfacing a new trend to use very large diameter metal-metal coupling with standard stem prostheses has been started. New prostheses, old and new problems. We analyze first failures with new large diameter metal on metal coupling.

The analysis focused on seven early failures of large diameter metal-metal prostheses (two resurfacing and five cementless prosthesis with XL head) over the first series of 350 cases (100 resurfacing and 250 cementless) in the first year. Synovial fluid aspiration have been performed in all failed patients searching for metal ions and bacterial proliferation. Moreover, prosthetic component positioning was also studied as a possible primum movens of these failures. Some failed patients underwent epicutaneous patch test for skin reaction to metal.

One resurface prosthesis failed as a result of an vascular necrosis and conseguent fracture of the femoral neck and revealed a moderate increment in metal ion concentration in blood and synovial fluid obtained at time of revision.

One resurface prosthesis failed as a result of an infected metallosis with a huge intraabdominal mass and revealed a huge increment in metal ion concentration in blood, addominal and synovial fluid. This patient underwent a lumbotomy to evacuate the abdominal retroperitoenal mass before prosthesis removal for a two step procedure.

Out of the five failures of metal on metal cementless prosthesis with XL head four were the result of aseptic loosening and one was the result of a low grade infection discovered at coltures after revision surgery. Three showed clear metallosis caused by wrong positioning (more than 50° of cup inclination). All of these three presented an articular noise and elevated blood and sinovial fluid metal ion concentration. The fourth patient with aseptic loosening had a good component positioning but demonstrated an epicutanous allergic reaction to Cobalt. Also one of the three patients with metallosis resulted allergic to Cobalt. The blood and sinovial metal ion values were always elevated but particularly high in patients with cup inclination over 50°.

Large head metal on metal prostheses demonstrated a higher percentage of early failure in our experience. They are very sensible to positioning. Blood and sinovial metal ion determination helps to promptly diagnose a bad metal on metal prosthetic functioning. A more accurate analysis about the different metals available on the market and their resistance to edge wear should not be delayed any further.


Orthopaedic Proceedings
Vol. 91-B, Issue SUPP_II | Pages 267 - 267
1 May 2009
Gobbi A Ramces F Arrigoni P
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Introduction: recent studies showed the possibility of spontaneous ACL healing in acute lesion with proper treatment. The goal of our study was to analyze the functional outcome of partial ACL tears treated acutely with suture-repair combined with a bone marrow stimulation (BMS) technique (microperforation). We hypothesized that knee stability could be restored and good functional outcome could be obtained with a simple primary repair technique.

Methods: From January 2003 to January 2006, 22 patients (14 males and 8 females – mean age: 23 years) with partial ACL rupture underwent acute primary ACL repair with our technique.

Inclusion-exclusion criteria:

anterior instability (confirmed intraoperatively by an isolated ACL tear),

surgery performed within 3 weeks from injury

. No grade 4 chondral defect,

no associated pathologies except for meniscal lesion

will to undergo to the same rehabilitation protocol.

Parameters analyzed included the standard knee scales (IKDC, Noyes, Lysholm and Tegner), SANE Score, Knee Laxity Analysis and Deep Flexion Tests. In 6 cases, second look arthroscopy was performed. All patients underwent a post-operative MRI.

Results: All these patients were available for follow up at 3/6 and final follow up (average of 18 months). Scoring systems revealed: Lysholm 93% (74–100), Tegner 7 (6–9), Noyes 80% (60–100) and Subjective (SANE) 86,22% (60–100). IKDC score demonstrated 55% group A, 36% B, 4% C and 4% D. This last patient didn’t go back to his previous activity level because of subjective apprehension. The knee was stable. Pivot shift test was negative in all the cases. Side to side difference was less or equal to 2 mm in all of our patients.

Conclusion: Based on the preliminary results, primary ACL repair with BMS can lead to favourable results in acute partial ACL lesion. However, further prospective randomized studies are recommended at longer follow-up to validate these findings.


Orthopaedic Proceedings
Vol. 91-B, Issue SUPP_II | Pages 268 - 268
1 May 2009
Randelli P Arrigoni P Randelli F Tassi A Cabitza P
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Aims: Healing of the rotator cuff after surgical repair continues to be one of the most challenging areas of shoulder surgery. Autologous Platelet Derived Grow Factors (PDGF) have been shown to positively affect the tissue healing, but their effect have not been studied in relation to tendon healing. The purpose of this study is to evaluate if the use of PDGF in rotator cuff surgery could lead to a better and faster healing of the repair.

Materials e Methods: We treated two groups (A,B) of 14 shoulders in 14 patients (mean age 66 and 63.4) with a full thickness rotator cuff tear. The group A and B were treated with a full arthroscopic repair of the cuff. In the group A, at the end of the procedure, the PDGF have been injected at the level of the lesion, between the tendon and the bone and over the tendon repair without irrigation and after the removal of all the cannulas. The group B, repaired in the same fashion, without PDGF, has been used as control.

In the group A the patients had an accelerated postop. rehabilitation. The group B received a standard rehabilitation protocol. Each group has been evaluated prospectively with VAS, UCLA and Constant scores pre-op and during follow-up.

Results: Both group showed an increase of the scores, compared to the pre-op. value (tab.1).

The VAS score of group A (PDGF) was pre-op. 5.6 and at 1 year 1.4. The VAS score of group B (no PDGF) was pre-op. 5.2 and at 1 year 1.4. The UCLA score of group A was pre-op. 16 and at 1 year 33.8. The UCLA score of group B was pre-op. 16.7 and at 1 year 32.9. The Constant score of group A was pre-op. 53 and at 1 year 90.7. The Constant score of group B was pre-op. 54.2 and at 1 year 90.1.

The complete statistical analysis of the data showed no significant differences in the results of the two groups (p< 0,01), with every kind of scores, VAS, UCLA and Constant, at the final follow-up of 1 year.

Conclusions: Our data suggest that the use of PDGF, compared to a standard repair, does not affect the quality of the rotator cuff repair at 1 year. Moreover the study suggest that the use of PDGF allows an accelerated rehabilitation program with ten days of immobilization compared to four weeks as usually prescribed. Further studies should clarify the real effect of PDGF about the acceleration of the first phase of the cuff healing.