Posterolateral fusion versus Dynesys dynamic stabilization: Retrospective study at a minimum 5.5years' follow-up

INTRODUCTION

Lumbar fusion is one of the most widespread techniques to treat degenerative lumbar pathology. To prevent complications such as non-union or adjacent segment degeneration, dynamic stabilization techniques were developed, but with controversial results. The aim of the present study was to compare long-term radiologic and clinical results between fusion and dynamic stabilization.

MATERIAL AND METHODS

A single-center retrospective study included patients with recurrent lumbar discal hernia or lumbar canal stenosis managed by posterolateral fusion or by dynamic stabilization associated to neurologic release. Patients were seen in follow-up for radiological and clinical assessment: visual analog pain scale (VAS), Oswestry Disability Index (ODI), Short Form-12 (SF-12), adjacent segment disease (ASD), and intervertebral range of motion (ROM).

RESULTS

Fifty-eight patients were included: 25 in the fusion group (FG), and 33 in the Dynesys^® group (DG). VAS scores were significantly lower in DG than FG. ODI was 14.6±2.8 in DG, versus 19.4±3.3 in FG (P=0.0001). SF-12 physical subscore was significantly higher in DG. ROM was 4.1±2° in DG, vs. 0.7±0.5° in FG (P=0.001). Radiologic ASD was significantly greater in FG than DG (36% vs. 12.1%; P=0.012), without difference in clinical expression (DG, 1 case; FG, 2 cases).

CONCLUSION

Dynamic stabilization provided clinical and radiological results comparable to those of posterolateral fusion in these indications (although level L5-S1 was not studied).

LEVEL OF EVIDENCE

IV.

Muscle recovery after ACL reconstruction with 4-strand semitendinosus graft harvested through either a posterior or anterior incision: a preliminary study

INTRODUCTION

Harvesting of a 4-strand semitendinosis (ST4) graft during anterior cruciate ligament (ACL) reconstruction can be performed through either a posterior or anterior approach. The objective of this study was to evaluate the recovery of the quadriceps and hamstring muscles as a function of the graft harvesting method. We hypothesized that posterior harvesting (PH) would lead to better recovery in hamstring strength than anterior harvesting (AH).

METHODS

In this prospective study, the semitendinosus was harvested through an anterior incision in the first group of patients and through a posterior one in the second group of patients. The patients were enrolled consecutively, without randomization. Isokinetic muscle testing was performed three and six months postoperative to determine the strength deficit in the quadriceps and hamstring muscles of the operated leg relative to the uninjured contralateral leg.

RESULTS

Thirty-nine patients were included: 20 in the AH group and 19 in the PH group. The mean quadriceps strength deficit after three and six months was 42% and 26% for AH and 29% and 19% for the PH, respectively (P=0.01 after three months and P=0.16 after six months). The mean hamstring strength deficit after three and six months was 31% and 17% for AH and 23% and 15% for the PH, respectively (P=0.09 after three months and P=0.45 after six months). After three months, the PH group had recovered 12% more quadriceps muscle strength than the AH group (P=0.03).

CONCLUSION

Our hypothesis was not confirmed. Harvesting of a ST4 graft for ACL reconstruction using a posterior approach led to better muscle strength recovery in the quadriceps only after three months.

CASE CONTROL STUDY

Level 3.

Odontoid fractures anterior screw fixation: a continuous series of 36 cases

INTRODUCTION

Fracture of the odontoid process represents 5 to 15% of cervical spine fractures. Anterior screw fixation is the reference technique in unstable posterior oblique or horizontal odontoid fracture.

OBJECTIVE

We describe results with an original anterior screw fixation technique using a curved thoraco-lumbar pedicle awl to facilitate intra-operative reduction.

PATIENTS AND METHODS

This is a retrospective study of 36 consecutive patients who underwent anterior screw fixation for odontoid process fracture. Mean age was 70.3 years. Twenty six patients had type II and 10 type III fracture on the Anderson-D'Alonzo classification. On the Roy-Camille classification, there were 34 posterior oblique fractures and two horizontal fractures. There were no anterior oblique fractures. Bony union was assessed on CT-scan at 3 months. We describe the surgical technique, which used a 4.5mm cannulated cancellous lag screw in all cases.

RESULTS

Mean follow-up was 3 years (range, 4 months to 8 years). No intra-operative complications were observed. Union rate was 95% and the average time to union was 5 months (3 to 6 months).

DISCUSSION

Anterior screw fixation is a common surgical treatment for posterior oblique and horizontal odontoid process fractures. We detail a reliable and reproducible intra-operative reduction maneuver to obtain a good union rate without complications.

LEVEL OF EVIDENCE

Level IV. Retrospective therapeutic study.

[High tibial open-wedge osteotomy using a tricalcium phosphate substitute: 70 cases with 18 months mean follow-up]

PURPOSE OF THE STUDY

We report our experience with a B tricalcium phosphate ceramic to fill open-wedge tibial osteotomy gaps.

MATERIAL AND METHODS

Seventy high tibial open-wedge osteotomies were performed in 70 patients (47 men and 23 women). Ostotomy was performed for osteoarthritis in 56 knees, Ahlback classification stage I (n = 18), stage II (n = 32), stage III (n = 6) and for congenital varus in 14. Mean patient age was 45.2 years (16-69). We used a wedge-shaped piece of ceramic with an appropriate angle, which was associated with granulated material to complete the gap filling for the last 20 cases. One or two staples were used for fixation. Clinical and radiological outcome was assessed at 6 weeks, 3 months, 6 months, and at last follow-up. Mean follow-up was 18 months.

RESULTS

There were no biological or clinical complications related to biomaterial intolerance. Tolerance to the osteosynthesis material was mediocre since we observed one infection and 12 cases of pain related to the staples which required material removal in 8 patients. Bone healing was achieved in 98.5%. Final correction was between 3 degrees and 6 degrees valgus in 80.5%. There was a loss of correction angle between the postoperative film and the bone healing film. Factors related to sustained correction were: non-fractured wedge, intact lateral tibial cortical, osteosynthesis with two staples. Osteointegration was good and rapid in 96%. We found two complete lucent lines at last follow-up but with variable resorption depending on the shape of the bone substitute.

CONCLUSION

Use of a ceramic wedge to fill high tibial medial open-wedge osteotomy gap is a reliable reproducible technique providing correction without formation of a malalignment callus. Bone healing is achieved in 98.5% of the cases at about three months. Osteointegration is good in 96%. Resorption is complete and rapid when the substitute is implanted in granular form in a cancellous zone and is partial and slow when implanted as a massive wedge.

Arthrodèse du genou par implant intra-médullaire sur mesure

We report our experience with knee arthrodesis using a customized intramedullary nail implanted in 14 patients. Indications for knee arthrodesis were: recurrent prosthesis infection (n=11), post-traumatic septic arthritis (n=1), aseptic loosening of a hinge prosthesis (n=1), and nonunion (n=1). A two-stage procedure was used for the 12 patients with infected joints. Mean follow-up was 19 months. Weight bearing began during the first week after arthrodesis in 13 patients. First intention bone healing was achieved in 13 patients. Mean time to healing was three months. All patients rapidly recovered full independence. Complications were: one misinsertion of the tibial stem, one nonunion which fused after repeated grafting, and two recurrent infections (controlled chronic fistulae) which required skin flaps for cover. We have found that this customized nail is a useful method for achieving bone fusion in patients with difficult indications for arthrodesis, particularly recurrent prosthesis infection.