Sigbjørn Dimmen

Worse patient-reported outcome after lateral approach than after anterior and posterolateral approach in primary hip arthroplasty: A cross-sectional questionnaire study of 1,476 patients 1–3 years after surgery

Background — The surgical approach in total hip arthroplasty (THA) is often based on surgeon preference and local traditions. The anterior muscle-sparing approach has recently gained popularity in Europe. We tested the hypothesis that patient satisfaction, pain, function, and health-related quality of life (HRQoL) after THA is not related to the surgical approach. Patients — 1,476 patients identified through the Norwegian Arthroplasty Register were sent questionnaires 1–3 years after undergoing THA in the period from January 2008 to June 2010. Patient-reported outcome measures (PROMs) included the hip disability osteoarthritis outcome score (HOOS), the Western Ontario and McMaster Universities osteoarthritis index (WOMAC), health-related quality of life (EQ-5D-3L), visual analog scales (VAS) addressing pain and satisfaction, and questions about complications. 1,273 patients completed the questionnaires and were included in the analysis. Results — Adjusted HOOS scores for pain, other symptoms, activities of daily living (ADL), sport/recreation, and quality of life were significantly worse (p < 0.001 to p = 0.03) for the lateral approach than for the anterior approach and the posterolateral approach (mean differences: 3.2–5.0). These results were related to more patient-reported limping with the lateral approach than with the anterior and posterolateral approaches (25% vs. 12% and 13%, respectively; p < 0.001). Interpretation — Patients operated with the lateral approach reported worse outcomes 1–3 years after THA surgery. Self-reported limping occurred twice as often in patients who underwent THA with a lateral approach than in those who underwent THA with an anterior or posterolateral approach. There were no significant differences in patient-reported outcomes after THA between those who underwent THA with a posterolateral approach and those who underwent THA with an anterior approach.

The effect of parecoxib and indometacin on tendon-to-bone healing in a bone tunnel AN EXPERIMENTAL STUDY IN RATS

Conventional non-steroidal anti-inflammatory drugs (NSAIDs) and newer specific cyclo-oxygenase-2 (cox-2) inhibitors are commonly used in musculoskeletal trauma and orthopaedic surgery to reduce the inflammatory response and pain. These drugs have been reported to impair bone metabolism. In reconstruction of the anterior cruciate ligament the hamstring tendons are mainly used as the graft of choice, and a prerequisite for good results is healing of the tendons in the bone tunnel. Many of these patients are routinely given NSAIDs or cox-2 inhibitors, although no studies have elucidated the effects of these drugs on tendon healing in the bone tunnel. In our study 60 female Wistar rats were randomly allocated into three groups of 20. One received parecoxib, one indometacin and one acted as a control. In all the rats the tendo-Achillis was released proximally from the calf muscles. It was then pulled through a drill hole in the distal tibia and sutured anteriorly. The rats were given parecoxib, indometacin or saline intraperitoneally twice daily for seven days. After 14 days the tendon/bone-tunnel interface was subjected to mechanical testing. Significantly lower maximum pull-out strength (p < 0.001), energy absorption (p < 0.001) and stiffness (p = 0.035) were found in rats given parecoxib and indometacin compared with the control group, most pronounced with parecoxib.

Negative effect of parecoxib on bone mineral during fracture healing in rats

Background and purpose Non‐steroidal anti‐inflammatory drugs (NSAIDs) are conventional cyclooxygen‐ase (cox) inhibitors commonly used in musculoskeletal trauma to reduce the inflammatory response and pain, but they also seem to affect bone metabolism. Parecoxib is a cox inhibitor that selectively inhibits cox-2. Through their selective mechanism of action, these newer drugs are supposed to reduce the gastrointestinal side effects of conventional cox inhibitors. The effects on bone metabolism and healing have, however, not been fully elucidated. Thus, there are reasons for concern regarding the potential negative effects of these drugs on bone metabolism and bone repair. We investigated the effects of short‐term administration of parecoxib on bone mineral formation and bone healing in rats. Animals and methods 26 female Wistar rats were given parecoxib intraperitoneally for 7 days after a closed tibial fracture that was stabilized with an intra‐medullary nail, and 26 animals were given saline. At 2, 3, and 6 weeks after surgery bone mineral density (BMD) at the fracture site was measured using dualenergy X‐ray absorptiometry (DEXA). 6 weeks after the fracture, 14 rats from the parecoxib group and 16 rats from the placebo group were killed for mechanical testing, and the rest of the animals were killed for tissue analysis. The healing fractures and the intact contralateral tibias were mechanically tested by three‐point cantilever bending. Results The BMD at the fracture site was calculated as the average of the results after 2,3, and 6 weeks. Mean BMD was lower in the parecoxib group, 0.23 (SD 0.06) g/ cm2, than in the control group, 0.27 (SD 0.05) g/cm2 (p = 0.01). There were no statistically significant differences in mechanical properties of the healing fractures after 6 weeks. However, the study may have lacked sufficient statistical power to determine whether a negative effect on healing had occurred. Interpretation No mechanical differences were detected between the control and treatment groups after 6 weeks, but they may have been present earlier in the fracture healing process. Our findings do, however, indicate that parecoxib given postoperatively for a week has a negative effect on mineralization during the early phase of fracture healing.

Long-term outcome of shoulder arthrodesis performed with plate fixation: 18 patients examined after 3-15 years.

Background and purpose There have been few reports on the long-term function after shoulder arthrodesis. We report the outcome after shoulder arthrodesis with plate fixation in 18 patients who were followed for 3–15 years. Methods 25 patients with a median age of 64 (19–75) years were operated with a shoulder arthrodesis between 1982 and 2003. Standard AO surgical technique with plating was used in all patients. 18 of the patients were examined retrospectively after a mean of 8 (3–15) years. 6 of the other patients had died and 1 refused examination. Results Radiologically, all but two arthrodeses fused completely. The remaining two were partially fused, within the glenohumeral joint or between humerus and acromion. The mean Oxford shoulder score was 32 and the mean ASES shoulder index was 59. Nine patients had intermittent or continuous pain; their mean pain score on a visual analog scale was 3. One patient had been re-operated after 4 months because of severe pain and 1 was operated due to a humeral shaft fracture after 8 months. 1 patient suffered from a complex regional pain syndrome. No infections occurred. Interpretation In this patient series there were few complications after shoulder arthrodesis, and the longterm functional results were acceptable.

Tendon to bone tunnel healing--a study on the time-dependent changes in biomechanics, bone remodeling, and histology in a rat model.

Tendons and ligaments attach to bone through a transitional connective tissue with complex biomechanical properties. This unique tissue is not regenerated during healing, and surgical reattachment therefore often fails. The present study was designed to evaluate tendon healing in a bone tunnel and to evaluate the utilized rat model. Wistar rats (n = 61) were operated with the Achilles tendon through a bone tunnel in the distal tibia. Healing was evaluated at 2, 3, 4, and 12 weeks by biomechanical testing, bone mineral density and histology. After 2 weeks median (interquartile range) pull‐out force was 2.2 N (1.9). The pull‐out force increased chronologically, by 12 weeks fivefold to 11.2 N (11.4). Energy absorption, stiffness, and bone mineral density increased similarly. The histological analyses showed inflammation at early stages with increasing callus by time. Our data showed a slow healing response the first 4 weeks followed by an accelerated healing period, favoring that most of the gain in mechanical strength occurred later than 4 weeks postoperatively. These findings support the concern of a vulnerable tendon bone tunnel interface in the early stages of healing.

A Trend for Increased Risk of Revision Surgery due to Deep Infection following Fast-Track Hip Arthroplasty

Rates of revision surgery due to deep infection following total hip arthroplasty (THA) increased at a Norwegian hospital following implementation of fast-track procedures. The purpose of this study was to determine whether selected demographic (age and sex) and clinical (body mass index, American Society of Anesthesiologists (ASA) classification, surgery duration, length of hospital stay, cemented versus uncemented prosthesis, and fast-track procedures) factors were associated with higher risk of revision surgery due to deep infection following THA. In a prospective designed study 4,406 patients undergoing primary THA between January 2001 and January 2013 where included. Rates of infection-related revision surgery within 3 months of THA were higher among males and among patients who received fast-track THA. Adjusting for sex and age, the implemented fast-track elements were significantly associated with increased risk of revision surgery. Risk of infection-related revision surgery was unrelated to body mass index, physical status, surgery duration, length of hospital stay, and prosthesis type. Because local infiltration analgesia, drain cessation, and early mobilization were introduced in combination, it could not be determined which component or combination of components imposed the increased risk. The findings in this small sample raise concern about fast-track THA but require replication in other samples.

Good functional results following high tibial opening-wedge osteotomy of knees with medial osteoarthritis

BACKGROUND To report time dependent functional improvement and predictive risk factors for failure when the load in varus knees with medial osteoarthritis is shifted from the medial to the lateral knee compartment. METHODS Forty-nine consecutive patients (52 knees), mean age 47 (31-64) years, underwent a high tibial opening-wedge valgus osteotomy stabilized with a Puddu plate and bone grafting. The patients were evaluated with the Knee Injury and Osteoarthritis Outcome Score (KOOS) preoperatively and at three and six months, one, two, five and 10years postoperatively with a mean follow-up time of 8.3years (2.0-10.6). RESULTS Mean angular correction was 8.0° (four to 12). The five subscores of KOOS increased significantly during the first year by 40-131% from preoperative values, the good results remaining throughout the 10-year follow-up for those with a surviving osteotomy. The outcome was related to the grade of preoperative osteoarthritis. Seven knees were converted to total knee arthroplasty (TKA) mean 6.2years (two to nine) post-operatively, and had a lower KOOS preoperatively than those of surviving osteotomies. The osteotomy survival rate at five years was 94% and at 10years 83%. Patients with KOOS subscore quality of life (QoL) <44 at the two-year follow-up had a 11.7 times higher risk for later TKA than those with QoL ≥44 (P=0.017). CONCLUSION High tibial opening-wedge osteotomy for medial knee osteoarthritis resulted in good functional recovery after one year and favorable mid-term results. It may be a good treatment option for middle-aged patients with varus knees and medial osteoarthritis in order to prevent or postpone TKA.

The Effect of Limited Perioperative Nonsteroidal Anti-inflammatory Drugs on Patients Undergoing Anterior Cruciate Ligament Reconstruction

Background: The administration of nonsteroidal anti-inflammatory drugs (NSAIDs) to patients undergoing anterior cruciate ligament reconstruction (ACLR) is controversial because it may impair tissue healing and clinical outcomes. Purpose: To assess the effect of NSAID administration on patients undergoing ACLR. Study Design: Cohort study; Level of evidence, 3. Methods: Included patients were aged >15 years and were registered in the Norwegian Knee Ligament Registry from 2008 until 2013 after the primary ACLR. Patients with insufficient data regarding administration of NSAIDs and those with associated knee ligament injuries requiring surgical treatment were excluded from this study. Graft survival was estimated using Kaplan-Meier survival curves, and hazard ratios (HRs) for revision were evaluated using Cox regression analysis. Logistic regression analysis was used to calculate the odds ratio (OR) for a Knee Injury and Osteoarthritis Outcome Score (KOOS)–quality of life (QOL) subscale score <44 at 2-year follow-up. Results: A total of 7822 patients were included in the analysis for graft survival and assessment for risk of revision. Of these, 4144 patients were administered NSAIDs postoperatively. The mean duration of follow-up was 2.8 years (range, 0-5.9 years). Administration of NSAIDs did not influence graft survival (P = .568). Adjusted Cox regression analyses demonstrated the same finding regarding risk of revision (HR, 1.0; 95% CI, 0.8-1.3). ACLR using a bone–patellar tendon–bone autograft showed a reduced risk of revision (HR, 0.3; 95% CI, 0.1-0.8) among patients administered NSAIDs. In subgroup analyses of 3144 patients, administration of NSAIDs demonstrated a beneficial effect on the risk of a KOOS-QOL score <44 at 2-year follow-up (OR, 0.8; 95% CI, 0.6-0.9). Conclusion: Administration of NSAIDs to patients after ACLR does not have a negative effect on graft survival, risk of revision, or risk of a KOOS-QOL score <44 at 2-year follow-up. We emphasize using caution when administering NSAIDs by keeping the duration and dosage of NSAIDs as short and low as possible to ensure sufficient pain relief while limiting unwanted exposure to any known and unknown adverse effects of these drugs.

Negative effect of zoledronic acid on tendon-to-bone healing: In vivo study of biomechanics and bone remodeling in a rat model

Background and purpose — Outcome after ligament reconstruction or tendon repair depends on secure tendon-to-bone healing. Increased osteoclastic activity resulting in local bone loss may contribute to delayed healing of the tendon–bone interface. The objective of this study was to evaluate the effect of the bisphosphonate zoledronic acid (ZA) on tendon-to-bone healing. Methods — Wistar rats (n = 92) had their right Achilles tendon cut proximally, pulled through a bone tunnel in the distal tibia and sutured anteriorly. After 1 week animals were randomized to receive a single dose of ZA (0.1 mg/kg IV) or control. Healing was evaluated at 3 and 6 weeks by mechanical testing, dual-energy X-ray absorptiometry and histology including immunohistochemical staining of osteoclasts. Results — ZA treatment resulted in 19% (95% CI 5–33%) lower pullout strength and 43% (95% CI 14–72%) lower stiffness of the tendon–bone interface, compared with control (2-way ANOVA; p = 0.009, p = 0.007). Administration of ZA did not affect bone mineral density (BMD) or bone mineral content (BMC). Histological analyses did not reveal differences in callus formation or osteoclasts between the study groups. Interpretation — ZA reduced pullout strength and stiffness of the tendon–bone interface. The study does not provide support for ZA as adjuvant treatment in tendon-to-bone healing.