3-T MRI assessment of osteophyte formation in patients with unilateral anterior cruciate ligament injury and reconstruction.

OBJECTIVE: To define the number and distribution of osteophytes (OPs) in bilateral knee MRI (magnetic resonance imaging) of patients with unilateral anterior cruciate ligament (ACL) rupture. MATERIALS AND METHODS: Bilateral knee MRIs of 20 patients with unilateral ACL rupture and reconstruction were retrospectively analyzed for OPs. OPs were graded following the KOSS (knee OA scoring system) classification and their compartmental distribution was assessed following the WORMS (Whole-Organ Magnetic Resonance Imaging Score) classification. RESULTS: All examined knees revealed OPs. Knees with ACL rupture showed significant (p < 0.001) higher total numbers of OPs (mean 11.6; SD ± 4.4) than knees with intact ACL (mean 5.1; SD ± 2.3). Knees with ACL rupture showed increased OP formation in all knee compartments with predominance of marginal OPs in the lateral femorotibial compartment especially on the tibia. CONCLUSIONS: Our results show that after knee injury with ACL rupture and reconstruction, all knee compartments were involved in post-traumatic increase of OP formation. The most affected compartment was the lateral femorotibial compartment on the tibial side.

Introduction of an alternative standardized radiographic measurement method to evaluate volar angulation in subcapital fractures of the 5th metacarpal.

OBJECTIVE: The purpose of the present study was to compare the intra- and interobserver reliability of two different measurement methods for volar angulation of the 5th metacarpal (MC) in an attempt to establish a new standard measurement method to reduce interobserver discrepancies for therapeutic decisions. MATERIALS AND METHODS: Twenty patients with subcapital fractures of the 5th MC were radiologically investigated. Imaging consisted of a radiographs in antero-posterior and precise lateral view in addition to a CT scan of the 5th MC. Measurement of volar angulation was accomplished using the conventional and the shaft articular surface (SAS) method. The measurements of five investigators were exported to a spreadsheet for statistical analysis to evaluate the intra-and interobserver reliability. RESULTS: The conventional technique showed large differences among the investigators and poor interobserver reliability (W = 0.328 and 0.307) both at injury (p = 0.001) and at follow-up (p = 0.189). The intraobserver concordance of all investigators showed better results with the SAS than with the conventional technique. With the SAS technique, no statistically significant difference among the investigators could be detected at either the time of injury (p = 0.418) or at follow-up (p = 0.526) with excellent interobserver reliability (W = 0.051 and W = 0.041). Evaluation of volar angulation at follow-up using CT scans did not show any statistically significant difference between the techniques with better correlation among the observers with the SAS technique (p = 0.838). CONCLUSIONS: The interobserver correlation of volar angulation with lateral radiographs using the conventional technique was insufficient. Therefore, we recommend the use of the novel SAS technique as standardized measurement method which showed higher accuracy and interobserver reliability in order to facilitate the choice of adequate treatment option. CLINICAL RELEVANCE: A CT scan should be performed in cases with ambivalent treatment options. LEVEL OF EVIDENCE: Evidence-Based Medicine Level II.

No increased occurrence of osteoarthritis after anterior cruciate ligament reconstruction after isolated anterior cruciate ligament injury in athletes.

PURPOSE: To evaluate the long-term radiographic and clinical results of anterior cruciate ligament (ACL) reconstruction by comparing the injured knee with the contralateral knee in athletes with isolated ACL tear returning to preinjury sports. METHODS: Twenty-eight patients with isolated ACL tears without concomitant injuries at baseline returning to previous sports were selected. ACL reconstruction was performed with patella or hamstring tendon graft. Conventional radiographs and a 3-T magnetic resonance imaging study of both knees were obtained at a mean follow-up of 10 years after ACL reconstruction and were compared with each other. The International Knee Documentation Committee score and Tegner activity index were used for clinical evaluation and the Knee Injury and Osteoarthritis Outcome Score for evaluating self-reported knee function. RESULTS: The 3-T magnetic resonance imaging study showed positive signs of osteoarthritis in 33% of operated knees and 39% of nonoperated knees (P = .64). Conventional radiographs showed ongoing signs of radiographic osteoarthritis in 14% of uninjured knees according to Kellgren and Lawrence, in comparison with 21% of injured knees (P = .73). The functional outcomes between the injured knee and uninjured knee did not show any statistical differences. The mean postoperative International Knee Documentation Committee score was 89.2 ± 9.3 points, and the total Knee Injury and Osteoarthritis Outcome Score was 92.7 ± 7.8. The median preinjury Tegner score was 8 ± 2, corresponding to 7 ± 2 at follow-up. In 68% of patients, the Tegner score was unchanged from preinjury to follow-up. CONCLUSIONS: Athletes with an isolated ACL rupture showed no increased risk of the development of post-traumatic osteoarthritis in the long-term after ACL replacement when compared with the uninjured contralateral knee. Our findings support the evidence to perform ACL replacement in athletes. LEVEL OF EVIDENCE: Level IV, therapeutic case series.

Efficacy of anterior odontoid screw fixation in the elderly patient: a CT-based biometrical analysis of odontoid fractures.

In the elderly population, reported union rates with anterior odontoid screw fixation (AOSF) for odontoid fracture (OF) treatment vary between 23 and 93% when using plain radiographs. However, recent research revealed poor interobserver reliability for fusion assessment using plain radiographs compared to CT scans. Therefore, union rates in patients aged ≥60 years treated with AOSF have to be revisited using CT scans and factors for non-union to be analysed. Prospectively gathered consecutively treated patients using AOSF for odontoid fracture with age ≥60 years were reviewed. Medical charts were assessed for demographics, clinical outcomes and complications. Patients' preoperative radiographs and CT scans were analysed to characterize fracture morphology and type, fracture displacement, presence of atlanto-dental osteoarthritis as well as a detailed morphometric assessment of fracture surfaces (in mm(2)). CT scans performed after a minimum of 3 months postoperatively were analysed for fracture union. Those patients not showing CT-based evidence of completely fused odontoid fracture were invited for radiographic follow-up at a minimum of 6 months follow-up. Follow-up CT-scan were studied for odontoid union as well as the number of screws used and the square surface of screws used for AOSF and the related corticocancellous osseous healing surface of the odontoid fragment (in %) were calculated. Patients were stratified whether they achieved osseous union or fibrous non-union. Patients with a non-union were subjected to flexion-extension lateral radiographs and the non-union defined as stable if no motion was detected. The sample included 13 male (72%) and 5 female (18%) patients. The interval from injury to AOSF was 4.1 ± 5.3 days (0-16 days). Age at injury was 78.1 ± 7.6 years (60-87 years) and follow-up was 75.7 ± 50.8 months (4.2-150.2 months). 10 patients had dislocated fractures, 14 had Type II and 4 "shallow" Type III fractures according to the Anderson classification, 2 had stable C1-ring fractures, 8 had displayed atlanto-dental osteoarthritis. Fracture square surface was 127.1 ± 50.9 mm(2) (56.3-215.9 mm(2)) and osseous healing surface was 84.0 ± 6.8% (67.6-91.1%). CT-based analysis revealed osseous union in 9 (50%) and non-union in 9 patients (50%). Union rates correlated with increased fracture surface (P = 0.02). Statistical analysis revealed a trend that the usage of two screws with AOSF correlates with increased fusion rates (P = 0.06). Stability at C1-2 was achieved in 89% of patients. CT scans are accepted as the standard of reference to assess osseous union. The current study offers an objective insight into the union rates of odontoid fractures treated with AOSF using CT scans in consecutive series of 18 patients ≥60 years. Literature serves evidence that elderly patients with unstable OF benefit from early surgical stabilization. However, although using AOSF for unstable OF yields segmental stability at C1-2 in a high number of patients as echoed in the current study, our analysis stressed that using follow-up CT scans in comparison to biplanar radiographs dramatically reduces osseous union rates compared to those previously reported for AOSF.