EOS-based cup navigation: Randomised controlled trial in 78 total hip arthroplasties.

BACKGROUND: Minimising the risk of cup implantation outside the safe zone is among the objectives of navigation during total hip arthroplasty (THA). However, given the technical challenges raised by navigation when the patient is lying on the side, many surgeons still use the freehand technique. We conducted a randomised controlled trial to evaluate the new navigation system NAVEOS in the iliac plane, which is easily identified in the lateral decubitus position, with the objective of determining whether NAVEOS navigation decreased the frequency of cup implantation outside the safe zone compared to freehand cup positioning, without increasing the operative time or the frequency of complications. HYPOTHESIS: NAVEOS navigation decreases the frequency of cup positioning outside the safe zone compared to freehand positioning. MATERIAL AND METHODS: This randomised controlled trial compared cup positioning using NAVEOS navigation versus the freehand technique in patients undergoing primary THA. The safe zone was defined according to Lewinnek as 15±10° of radiological anteversion and 40±10° of radiological inclination. Cup position parameters were measured on computed tomography images obtained 3months after THA. The images were read by two independent observers who were blinded to group assignment. The primary evaluation criterion was cup position within the safe zone. RESULTS: A 1:1 randomisation scheme was used to assign 78 patients (mean age, 68years; age range, 44-91years) to NAVEOS navigation or freehand cup positioning. The two groups were comparable for age, gender distribution, body mass index, and preoperative functional scores. In the NAVEOS group, navigation was discontinued prematurely in 6 patients, because of technical difficulties (n=2) or a marked discrepancy with clinical findings (n=4); however, the intention-to-treat approach was used for the analysis. The proportion of cups in the safe zone was 67% (28/39) in the NAVEOS group and 38% (17/39) in the freehand group (P=0.012). Anteversion was within the 5-25° range for 72% (28/39) cups in the NAVEOS group and 46% (18/39) in the freehand group (P=0.021). Inclination was within the 30-50° range for 95% (37/39) of cups with NAVEOS navigation and 85% (33/39) with freehand positioning (P=0.135). The odds ratio for cup implantation outside the safe zone was significantly lower with NAVEOS compared to freehand positioning (0.54; 95% confidence interval, 0.31-0.91). Mean operative time was 74 (range, 45-115) minutes with NAVEOS navigation and 70 (range, 40-105) minutes with freehand positioning (P=0.382). Complications consisted of 1 case each of anterior dislocation and infection, both in the freehand group. DISCUSSION: Compared to freehand positioning, NAVEOS navigation significantly lowered the risk of cup positioning outside the safe zone, chiefly via improved achievement of the anteversion target. NAVEOS was not associated with increases in operative time or morbidity. LEVEL OF EVIDENCE: II, randomised controlled trial with limited statistical power.

Arthroscopic resection of benign tumors of the knee posterior compartment: a report of 15 cases.

INTRODUCTION: The management of tumors located in the posterior compartment of the knee, whatever the nature of the tumor, remains surgical excision and can be done by open surgery or under arthroscopic control. The objective of this study was to evaluate the arthroscopic management of intra-articular tumors of the posterior compartment of the knee. The hypothesis is that tumors or tumor-like lesions confined to the posterior compartment are accessible by arthroscopy with low iatrogenic risk. MATERIALS AND METHODS: All patients with an intra-articular tumor of the posterior compartment of the knee were enrolled between 2009 and 2013. The surgical management consisted of arthroscopic resection. Patients underwent postoperative MRI, repeated at last follow-up. The outcomes were the occurrence of complications, functional evaluation using the Lysholm Knee Scoring Scale, and the recurrence rate. RESULTS: Fifteen patients were included. All patients had a complete resection. One case of delayed healing of the arthroscopic entry point was observed. At a mean 22months, the mean Lysholm Knee Score increased from 74 (±8.5) preoperatively to 92 (±7.7) postoperatively, a significant increase of 18 points (P=0.001). One patient had a recurrence of osteochondromatosis, requiring removal of a foreign body. DISCUSSION: Resection of posterior intra-articular tumors of the knee using arthroscopy is possible, subject to a learning curve.

Reconstruction of femoral bone loss with a monoplane external fixator and bone transport.

BACKGROUND: Treatment of femoral bone loss is difficult. Ilizarov described the bone lengthening technique using a circular external fixator, but this technique is uncomfortable on the femur because of the circular fixator. We have therefore opted for use of a monoplane external fixator to treat femoral bone loss with bone lengthening. The objectives of this study were to determine whether (1) bone union can be obtained with a monoplane external fixator; (2) infections can be treated; (3) the lower limb axes and alignment can be controlled; and (4) patient satisfaction is high. HYPOTHESIS: A monoplane external fixator provides a high rate of bone union during bone transport with no risk of deformity over the long term. MATERIAL AND METHODS: Between 2007 and 2012 seven patients were treated with bone transport using a monoplane external fixator for femoral bone loss measuring a mean 8.1cm (range, 6-10cm). All were infected (osteomyelitis) or contaminated following Gustilo type IIIB fractures. The mean time from initial injury to the beginning of bone loss management was 3.9months (range, 1.5-8 months) for six of them and 108 months for one patient. RESULTS: At the mean follow-up of 4.7 years (range, 2-7 years), all of the patients showed union after a mean 11.1months (range, 8-18 months), i.e., 41.2 days/cm of transport, and all infections were resolved. Only one patient had unequal leg length measuring 2cm and another showed 3° varus. Five patients were satisfied despite disappointing functional results. All could fully extend the knee but the mean flexion was 50° (range, 20-90°). DISCUSSION: This series confirms that use of the monoplane external fixation with descending bone transport to treat infected femoral bone loss is efficient and provides bone union, treatment of the infection, and control of bone axes and lengths. This technique does not allow recuperation of complete knee flexion. LEVEL OF EVIDENCE: IV, retrospective study.

A rare coronal fracture of the medial carpal column: Case report.

Carpal coronal fractures are rare. We report the case of a 15 year-old male who fell from a balcony and suffered a displaced coronal fracture of the capitate, hamate and triquetrum. The diagnosis, which was initially made based on the X-rays, was confirmed by CT scan. Open reduction and internal fixation using Herbert screws was performed. To the best of our knowledge, this is the first published case of a coronal fracture of these three bones. The patient returned to normal activities after six months.

Arthroscopic treatment of an intra-articular hemangioma in the posterior compartment of the knee.

We report the case of a 37-year-old patient presenting with knee pain and recurrent effusion without instability due to an intra-articular hemangioma in the posterior compartment of the knee. MRI showed features suggesting a diagnosis of hemangioma. Arthroscopic excision of the tumor was performed and the diagnosis was confirmed histologically. There was no recurrence after 5 years of follow-up.

Isolated anterior interosseous nerve deficit due to a false aneurysm of the humeral artery: an unusual complication of penetrating arm injury. Case report and literature review.

Anterior interosseous nerve (AIN) injuries account for only 1% of all the nerve injuries at the upper limb. We report the case of a 22-year-old male who sustained a penetrating injury to the arm. No neurological deficit was found at the initial evaluation. However, 6 weeks later, he had a motor deficit confined to the territory of the AIN with weakness of the flexor pollicis longus and flexor digitorum longus to the index. He also reported paraesthesia. Tinel's test was positive over the pinpoint wound in the arm, where a painful swelling was felt. Electroneurophysiological testing indicated a deficit of the AIN. Surgical exploration identified a thrombosed false aneurysm of the humeral artery responsible for compression of the median nerve. One month later, the patient had achieved a full recovery. Immediate routine exploration of deep penetrating wounds, although mandatory, may fail to detect any lesions. Close monitoring must be provided subsequently, as gradual nerve compression can result in delayed neurological deficits.