Poor outcome in ACL reconstruction is often related to tunnel position. This study investigates the use of surgical navigation to improve outcome. Improving accuracy of tunnel position will lead to improved outcome.

In a prospective randomised controlled trial 60 ACL plasties with quadruple-loop semi-tendinosus and gracilis tendon were randomised to either standard instrumentation or computer assisted guides to position the tibial and femoral tunnels. The results were evaluated on clinical outcome based on IKDC laxity measurements and radiologic assessment of anterior drawer at 150 and 200N as well as radiological assessment of the tunnel positions.

No complications were observed in either group. IKDC laxity was level A in 22 knees in the conventional group (average 1.5 mm (0-6) at 200N) compared with 26 navigated knees (average laxity 1.3mm (0-5)). Laxity was less than 2 mm in 96.7% of the navigated group (83% in conventional group). The variability of laxity in the navigated group was significantly less than the conventional group, with the standard deviation of the navigated group being smaller than the conventional group standard deviation (p = 0.0003 at 150N and 0.0005 at 200N TELOS).

A significant difference (p=0.03) was found between the groups in the ATB value characterising the sagittal position of the tibial tunnel (negative ATB values imply graft impingement in extension). In the conventional group mean ATB was -1.2 (-5-+4) while it was 0.4 (0 - 3) in Group II. There were no negative ATB values in the Navigated Group.

The use of computer assisted navigation creates a more consistently accurate tibial tunnel position than using conventional techniques. It is suggested that this should reduce impingement and improve graft longevity.

Purpose of the study: Anterior cruciate ligament (ACL) navigation systems are based on two underlying principles: «statistical» anatomic position and isometric anatomic (anatomometric) positioning. The purpose of this study was to demonstrate that an anatometric positioning of the transplant can be achieved, in other words, that the transplant can be positioned in the original anatomic air of the ligament insertion while preserving an optimal isometry without notch impingement. This study was also conducted to compare conventional systems with a computer-assisted system.

Material and methods: This study was conducted on thawed fresh-frozen cadaver knee specimens with > 120° flexion. The computer-assisted protocol for ACL surgery was applied to ten knee specimens. The original anatomic insertions of the ACL were dissected then inserted at the appropriate points into the computer display. The tibial and femoral insertion points of two classical aiming devices were recorded. These points were compared with the original anatomic insertion.

Results: For the tibia: classical aiming methods proposed a point of insertion posterior to the anatomic insertion for eight knees and within the frontiers of the anatomic insertion for two, in line with the anterior border of the posterior cruciate ligament. The computer-designated point of insertion for the tibial fixation was always within the anterior third of the ACL insertion, generally medially. For the femur, the transition (or isometric) line ran across the anatomic femoral insertion in all knees. It was observed that in all cases, the surgeon could choose an anatomic insertion with lesser anisometry by situating the insertion in the distal part of this line: for nine knees, the computer-designated femoral point was anatomic and with lesser anisometry. The Acufex aiming device produced better anisometry (my=4 mm) than the Arthrex device (my=6 mm) but with a less favorable anisometry curve.

Discussion: The notion of anatometry is compatible with computer-assisted surgery. This study demonstrated that the computer-designated tibial point of insertion is more anterior and medial than the conventional aiming points. This is a potential choice if the absence of a notch impingement can be visualized: Howel described a manual fluoroscopic method. In our opinion, at the present time, optimal choice of the femoral point to achieve the desired anisometric curve is strictly operator-dependent.

Purpose of the study: For medial osteoarthritis with chronic anterior laxity, we propose an original technique combining subtraction osteotomy and extra-articular ligmentoplasty using the lateral quarter of the patellar tendon.

Material and methods: WE report a retrospective review of 29 patients (11 males/18 females) aged 29–51 years treated from May 1996 to October 2002. Time from rupture of the anterior cruciate ligament (ACL) and the operation was 17.5 years (range 13–22 years). These patients had had 52 prior operations (more than one per knee). All presented functional instability, a positive pivot test, and anterior laxity measured at 8 mm on average (range 5–10 mm) on KT1000. Pain in the medial compartment was observed in all patients with osteoarthritis noted grade II in 7, grade III in 18 and grade IV in 4. Radological varus measured 5–15°. Lateral subtraction osteotomy fixed with a plate was performed in combination with a patellar tendon autograft using the lateral quarter of the patellar tendon. Immediate mobilization with complete weight bearing was the rule.

Results: A mean 5–year follow-up (range 18 months to 9 years). According to the IKDC subjective score, 26 patients were satisfied or very satisfied and 22 of them had resumed their sports activities. Instability persisted in one patient and pain in two. Varus was corrected in three patients but the medial degradation progressed. Anterior laxity measured with KT1000 was 1–6 mm (mean 2 mm). The pivot test was positive in one knee, negative in 18 and revealed slight displacement in 10. Excluding the radiological aspect, the overall IKDC score was 2A, 21B, 6C, 1D.

Conclusion: This combined method is particularly interesting for stabilizing chronic ACL instability causing secondary medial degeneration. It treats two conditions with the same approach with an acceptable rate of satisfaction.

Purpose: Chronic ankle instability is generally related to lateral laxity of the tibiotalar joint. Stress x-rays may however be negative. Varus of the hindfoot is another possibility. In such cases, it would be logical to propose Dwyer valgus osteotomy of the calcaneum. The objective of this work was to review patients who underwent Dwyer osteotomy from 1992 to 2000.

Material and methods: The series included fifteen patients, nine men and six women, who complained of chronic ankle instability with no evidence of laxity. All presented a varus hindfoot (mean 5°, range 3–10°). Thirteen patients practiced sports, including eight at the competition level. Sixty percent had experienced instability accidents during sports activities. Associated lesions were fissures of the fibular tendons (n=2), osteochondral lesion of the talar dome (n=1), Haglund disease (n=1) and stage II pes cavus (n=2). Lateral closed Dwyer osteotomy was performed in all cases, generally with fixed with two screws in a 2-hole 1/3 plate. Associated procedures were: lateral ligamentoplasty (n=1), osteotomy to raise M1 (n=2), regularisation of an osteochondral lesion of the talar dome (n=1), Zadek osteotomy (n=1) and anterior arthrolysis (n=1). The same surgeon reviewed the patients clinically and radiologically, independent of the operator.

Results: Mean follow-up was 3.5 years (range 1–9, SD 2.5). There were no complications except one case of cutaneous necrosis in the patient who had simultaneous osteotomy and ligamentoplasty. Instability resolved in all patients. Ten patients experienced minor episodic pain (50% during sports activities). Eleven patients (70%) resumed their sports activities within eight months (3–36) and 33% at their former level. The mean Kitaoka score was 92 (85–100) and 80% of the patients were satisfied or very satisfied.

Conclusion: Dwyer osteotomy provides quite satisfactory results for patients with chronic ankle instability without evidence of laxity and hindfoot varus. When a complementary ligamentoplasty appears to be necessary, it is preferable to wait for a second operation in order to avoid the risk of cutaneous necrosis.

Purpose: The purpose of this work was to study the reliability and the precision of a lumber vertebra reconstruction method using images obtained from a 3D statistical model and two calibrated radiograms. The technique is designed for surgical approach to the lumbar spine and implantation of osteosynthesis material using enhanced-reality technology.

Material and methods: A lumbar vertebra was reconstructed on several specimens using images issuing from a 3D statistical model and two calibrated radiograms. The images obtained from the model of this lumbar vertebra to be reconstructed constituted the preoperative images. Intra-operative images corresponded to two calibrated radiograms acquired with a fluoroscope using advanced technology (silicium receptor). The model was equipped with reflecting patches which can be detected in space using a 3D optical system. Correspondence between the 3D statistical model and the two calibrated radiograms was achieved with appropriate software. Navigation views were displayed on the screen to guide surgical tools at the vertebral level. Pedicular screws were implanted into several anatomic specimens to evaluate the reliability and precision of the system. The exact position of the implanted screws was established with computed tomography.

Results: This system demonstrated its reliability and precision for the reconstruction of a lumbar vertebra from a 3D statistical model and two calibrated radiograms. All the implanted screws were perfectly positioned in the pedicles. Precision was to the order of 1 mm.

Discussion: This method is a passive system not requiring intraoperative intervention. Reconstruction of a lumbar vertebra from a preoperative 3D statistical model and two intra-operative calibrated radiograms avoids the need to identify anatomic landmarks and/or surface points on the vertebra to be reconstructed. The level of precision is very similar to that obtained with CT-based systems. Preoperative CT is not needed for navigation.

Conclusion: With this system, new generation fluoroscopic equipment should appear in the operating room, allowing acquisition of successive calibrated images. The digital data could then be matched with statistical anatomic data, avoiding the need for preoperative imaging (CT or MRI). Progressive introduction of intra-operative ultrasound to replace the calibrated radiograms should open a new approach for percutaneous surgery of the lumbar spine.

Aims: Hindfoot deformity in varus position is an aetiology of chronic ankle instability without laxity. In this condition, a Dwyer osteotomy has to be performed.

Methods: Between 1992 and 2000, 15 patients have been operated on, with this technique. The mean varus deformity was of 5û (3û to 10û).13 patients had sporting activities, 8 of them in competition. Instability during sporting activity were present in 60% of cases. Associated lesions were reported in 6 cases. A Dwyer procedure using a 1/3 tube plate þxed with two screws were performed in all cases. Associated procedures were performed at the same time as such as a lateral ligamentoplasty or a þrst metatarsal osteotomy. All patients were reviewed clinically and radiologically using AOFAS score.

Results: The mean follow-up was of 3.5 years (1 to 9 years). The only one complication reported was a skin necrosis, treated by a cutaneous ßap in a patient operated on with Dwyer and ligamentoplasty in the same procedure. No ankle instability was reported. Mild pain was reported in 10 patients and 50% of them only for sporting activities.11 patients returned to sporting activity and 33% of them at the same level. The mean Kita-oka score was of 92 (85 to 100). The patients were satisþed and very satisþed in 80 of cases.

Conclusions: Dwyer lateral closing wedge calcaneal osteotomy is successful for the treatment of chronic ankle instability without laxity and with varus hindfoot deformity. When laxity is associated with varus deformity an operative procedure in two steps is necessary to avoid wound complication. Dwyer osteotomy has to be performed þrst.

Purpose: This study analysed nerve trunk injury associated with posterior fractures of the pelvic girdle, distinguishing initial post-trauma damage from morbidity correlated to treatment by reduction and iliosacral screw fixation.

Material: Fifty bone or ligament injuries to the posterior pelvic girdle were identified in 44 patients. Management included initial external reduction and differed fixation using iliosacral screws inserted under fluorescence guidance.

Methods: The metameric examination of the lumbar and sacral trunks (L2, L3, L4, L5, S1, S2, S3) was performed at admission when the patient was conscious. The postoperative work-up included a complete neurological exam and computed tomography assessment of the screw trajectory. The quality of the reduction was quantified on the anterioposterior view of the pelvis. At last follow-up, evolution of symptoms ± EMG, Trendenburg gait, Mageed score, QMS score and pain (assessed on a visual analogue scale) were recorded.

Results: Preoperatively, 14 deficits of the nerve trunks were identified. The neurological status was unknown for eleven bone and ligament injuries because the patients were sedated at admission. Postoperatively, 28 deficits were identified. Fourteen (50%) involved the lumbosacral trunks L4 and L5, five the S1 root, six L4, L5, S1 territories, and three L5 to S4.

Computed tomography demonstrated 15 extraosseous screws lying anteriorly to the sacral ala or in the sacral canal. These extraosseous screws were associated with neurological deficits in nine cases without a preoperative diagnosis. In six cases, the extra-ossesous screw was not associated with any postoperative deficit. In five cases, neurological lesions diagnosed after the operation were not associated with an extra-osseous screw. Twenty-six neurological lesions were reviewed at a mean follow-up of 25 months: improvement was observed in 19, no change in five and aggravation in two.

Conclusion: Initial diagnosis of neurological injury with precision of the localisation can be established for only half of pelvic girdle fractures. The main mechanism involves stretching of the lumbosacral trunk by displacement of the sacral ala. Injury to the superior gluteal nerve is often associated. Closed reduction or compression of a nerve trapped in the fracture gap during screw fixation could be a second mechanism. Finally, rigorous screw insertion is necessary to avoid extra-osseous trajectories lying anteriorly to the sacral ala.

Purpose: Injury of both cruciate ligaments raises difficult therapeutic problems in trauma victims. The severity of such lesions is related to the context of multiple trauma and to the general regional context associating vascular and neurological injury. Therapeutic management should be multidisciplinary to determine the appropriate strategy. Orthopaedic treatment should take into account the different diagnostic and therapeutic aspects. The purpose of this work was to detail ligament injuries observed and to assess results of treatments proposed.

Material and methods: This retrospective series included 20 patients (14 men and 6 women), mean age 33 years (18–54). Five had multiple trauma with head injuries and multiple fractures. The initial diagnosis was traumatic knee dislocation in 14 patients. Seven patients underwent emergency vascular explorations with subsequent femoropopliteal bypass (n=3). Neurological lesions included three cases of complete section of the lateral popliteal sciatic. Orthopaedic treatment was used in three cases. We used external fixation for two months on the average in three patients. Six others underwent surgery (less than eight days after injury) after obtaining an MRI. The surgical strategy was based on several arguments: age, general status, level of the ligament injury. Three patients underwent secondary surgery on the anterior cruciate ligament. Outcome was assessed at a mean follow-up of 36 months (20–60). The clinical assessment of the objective result was based on frontal and sagittal laxity. The subjective result and the level of sports activities were also recorded. Radiographically, we studied the standard x-rays in single leg stance and also the stress images using telos with anterior then posterior drawer.

Results: Excepting one case of amputation necessary due to the vascular and nervous injuries, orthopaedic treatment allowed an acceptable functional result in sedentary patients: good frontal stability and minimal anteroposterior residual laxity. Fourteen athletes underwent emergency surgery to repair the posterior cruciate ligament: posterior approaches in eight knees with injury of the floor with no posterior drawer at last follow-up; anterior approaches in six knees for suture of the posterior cruciate ligament and insertion of a synthetic ligament tutor with anterior cruciate ligament repair during the same operative time (two floor reinsertions, one patellar tendon plasty, and three Cho plasties). The stability of the posterior pivot was excellent but the tibial reinsertions of the anterior cruciate ligament failed. Seven knees required mobilisation under general anaesthesia 2.5 months later. Three knees underwent secondary anterior cruciate repair using the Kenneth Jones technique with negative Lachmann at last follow-up.

Discussion: Excepting vascular and neurological emergencies dictating the initial therapeutic attitude, our orthopaedic management was based on a detailed identification of the lesion using emergency MRI: anterior or posterior approach, anterior cruciate repair technique dependng on association with peripheral ligament injury. Good results in terms of posterior laxity were achieved in this series, confirming the importance of emergency repair of the posterior cruciate. If the medial ligaments are intact, the anterior cruciate can be repaired in the emergency setting with a Cho plasy. In other situations, we prefer waiting before surgical repair of the anterior pivot.