Thickness of the bone-cartilage unit in relation to osteoarthritis severity in the human hip joint.

OBJECTIVE: Bone formation is a hallmark of osteoarthritis (OA). It has been speculated that bone formation may occur because of ossification at the bone-cartilage unit, that is, bone formation directly involving the calcified cartilage (CC). This study aimed to investigate the thickness of the CC and subchondral bone (SCB) in relation to the severity of the overlying articular cartilage (AC) degeneration. DESIGN: We investigated femoral heads from 20 patients with OA and 15 healthy subjects with design-based stereology using systematic uniform random sampling of the entire joint surface. This was combined with the Osteoarthritis Research Society International (OARSI) OA cartilage histopathology assessment system, thus obtaining focal OARSI grades paired with thickness measurements of AC, CC and the SCB. RESULTS: The patients with OA had thicker CC (mean 159; 95% CI 144 to 177 µm) compared with the healthy subjects (mean 132; 95% CI 113 to 1550 µm; p=0.036), and this difference was even higher in areas without loss of AC thickness (OARSI grade ≤3); 187 (95% CI 164 to 214) µm vs 132 (95% CI 113 to 155) µm (p=0.001). In the patients with OA, a thicker SCB was observed in areas with loss of AC thickness (OARSI grade ≥4), but not in areas without loss of AC thickness (OARSI grade ≤3). CONCLUSION: The study showed that thicker CC is present in early stages of OA, suggesting that bone formation by endochondral ossification is an early phenomenon of OA. Thickening of the SCB was present, but only in areas with denuded bone. Suggesting that also appositional bone growth occurs and that it may be a consequence of changed biomechanics.

The influence of pre- and perioperative administration of gabapentin on pain 3-4 years after total knee arthroplasty.

BACKGROUND AND AIMS: Approximately 20% of patients having total knee arthroplasty (TKA) will experience chronic postoperative pain. Recently, preoperative pain facilitation has been associated with chronic pain after TKA, and gabapentin has been shown to decrease pain facilitation. The current study is a secondary follow-up of a primary RCT investigating the effect of gabapentin on acute postoperative pain after TKA and exploring the effect of pre- and perioperative administration of gabapentin on chronic postoperative pain and psychological state 3-4 years after TKA. METHODS: Patients scheduled for TKA were randomized to either gabapentin 1,300 mg/day, gabapentin 900 mg/day, or placebo daily from 2-h before and 6 days after operation. Pre- and 3-4 years postoperatively pain scores related to pain while walking, at rest, when flexing the hip or the knee were collected. At the same time, the pain catastrophizing scale (PCS) and hospital anxiety and depression scale subscales for anxiety (HADS-A) and depression (HADS-D) were collected. RESULTS: Lower postoperative pain while walking, flexing the hip, and at rest were found compared with preoperative scores (p<0.03), but these were not associated with gabapentin treatment (p>0.19). Significantly lower postoperative PCS and HADS-A scores were seen compared with preoperative scores (p<0.001), but these were not associated with gabapentin treatment (p>0.55). CONCLUSIONS: The current study found that pre- and perioperative administrations of gabapentin do not influence the pain or psychological state 3-4 years after TKA. IMPLICATIONS: The current study does not support that short-term pre- and perioperative use of gabapentin can reduce the development of chronic postoperative pain after TKA.

Prospective psychometric characterization of hip and knee arthroplasty patients.

BACKGROUND: Psychiatric conditions and psychopharmacological treatments have been demonstrated to be important risk-factors for prolonged hospital length of stay, readmission and morbidity, following fast-track total hip (THA) and total knee arthroplasty (TKA). AIMS: The aim of the study was to provide a detailed description of the preoperative psychiatric characteristics of a well-defined patient population undergoing THA and TKA, using the 90-item Symptom Checklist (SCL-90-R). METHODS: A pre-surgical population of 2183 patients completed the full SCL-90-R prior to THA/TKA from 2015 to 2016. The SCL-90-R scale and total scores of the pre-surgical sample were compared to the scores of an age- and gender stratified Danish sample of healthy controls. A Mokken scalogram analysis was conducted to assess the scalability of the SCL-90-R in both samples. RESULTS: The Mokken analysis yielded acceptable scalability coefficients above 0.30 in all subscales of the SCL-90-R except psycoticism (0.28). There was no clinically significant difference (effect size = <0.50) in the SCL-90-R total score between the pre-surgical and the healthy controls samples, although pre-surgical patients had lower mean scores compared to the healthy controls in all subscales except somatization (effect size = -0.22). CONCLUSION: The Mokken analysis demonstrated that the SCL-90-R and its subscales express valid measures of psychopathology in our surgical sample. The psychiatric profile of the pre-surgical patient sample indicates that patients undergoing THA/TKA are not more burdened by psychiatric symptoms than a healthy control group with the exception of symptoms relating to somatization.

Thresholds for Oxford Knee Score after total knee replacement surgery: a novel approach to post-operative evaluation.

BACKGROUND: In a prospective cohort study, we wanted to detect thresholds distinguishing between patients with a satisfactory and an unsatisfactory outcome after total knee replacement (TKR) based on Patient-Reported Outcome Measures (PROMs), namely the Oxford Knee Score (OKS), using patient satisfaction and patient-perceived function as global transition items. METHODS: Seventy-three TKR patients completed the OKS questionnaire before surgery and were invited to complete the same questionnaire again 6 (4 to 9) months after surgery. Correlations between outcome measures and anchors were calculated using Pearson's correlation coefficient. Thresholds were established by receiver operating characteristics (ROC) analysis, using multiple anchor-based approaches. RESULTS: Patients showed a mean increase of 16.5 (SD 9.5) in OKS following TKR. Significant positive correlations were found between outcome measures and anchors. Six different thresholds were determined for outcome measures coupled with satisfaction, patient-perceived function and a combination thereof using a cut-off of 50 and 70. CONCLUSIONS: This study has established a set of clinically meaningful thresholds for Oxford Knee scores that may help to detect TKR patients who might be in need of post-operative evaluation.

Safety Aspects of Postanesthesia Care Unit Discharge without Motor Function Assessment after Spinal Anesthesia: A Randomized, Multicenter, Semiblinded, Noninferiority, Controlled Trial.

BACKGROUND: Postanesthesia care unit (PACU) discharge without observation of lower limb motor function after spinal anesthesia has been suggested to significantly reduce PACU stay and enhance resource optimization and early rehabilitation but without enough data to allow clinical recommendations. METHODS: A multicenter, semiblinded, noninferiority randomized controlled trial of discharge from the PACU with or without assessment of lower limb motor function after elective total hip or knee arthroplasty under spinal anesthesia was undertaken. The primary outcome was frequency of a successful fast-track course (length of stay 4 days or less and no 30-day readmission). Noninferiority would be declared if the odds ratio (OR) for a successful fast-track course was no worse for those patients receiving no motor function assessment versus those patients receiving motor function assessment by OR = 0.68. RESULTS: A total of 1,359 patients (98.8% follow-up) were available for analysis (93% American Society of Anesthesiologists class 1 to 2). The primary outcome occurred in 92.2% and 92.0%, corresponding to no motor function assessment being noninferior to motor function assessment with OR 0.97 (95% CI, 0.70 to 1.35). Adverse events in the ward during the first 24 h occurred in 5.8% versus 7.4% with or without motor function assessment, respectively (OR, 0.77; 95% CI, 0.5 to 1.19, P = 0.24). CONCLUSIONS: PACU discharge without assessment of lower limb motor function after spinal anesthesia for total hip or knee arthroplasty was noninferior to motor function assessment in achieving length of stay 4 days or less or 30-day readmissions. Because a nonsignificant tendency toward increased adverse events during the first 24 h in the ward was discovered, further safety data are needed in patients without assessment of lower limb motor function before PACU discharge.

Facilitated temporal summation of pain correlates with clinical pain intensity after hip arthroplasty.

Widespread hyperalgesia has been found in patients with painful hip osteoarthritis (OA) which can be normalized after total hip arthroplasty (THA) if patients have no residual postoperative pain. This study characterized the preoperative somatosensory profiles and provided possible interpretation of underlying pain mechanisms that might influence the development of postoperative pain. Forty hip OA patients with unilateral pain were assessed before and 6 weeks post-THA and compared with 40 asymptomatic control subjects. Hip pain intensity at rest and while walking was assessed on a visual analogue scale (VAS). Bilateral cuff algometry from the thighs was used to assess the cuff pressure pain thresholds, pressure values at VAS scores equal with 6 cm (PVAS6), cuff pressure tolerance, and temporal summation of pain (TSP) quantified by an increase in VAS scores to repeated phasic cuff stimulations. Correlations between hip pain VAS post-THA and preoperative quantitative sensory testing results were analyzed. Post-THA hip pain VAS scores decreased (P < 0.05) compared with pre-THA. The cuff pressure pain threshold, PVAS6, and cuff pressure tolerance were significantly lower bilaterally in both patients with pre-THA and post-THA compared with controls (P < 0.05). Temporal summation of pain was facilitated bilaterally in patients with pre-THA compared with controls and normalized after THA in postoperative pain-free patients (P < 0.05). Postoperative hip pain VAS scores correlated with preoperative ipsilateral TSP (r = 0.44, P < 0.05). Bilateral pressure pain hypersensitivity and facilitated TSP were demonstrated in patients with preoperative hip OA. Although persistent postoperative pain is known as multifactorial, greater preoperative TSP was associated with greater pain and less reduction in pain after THA.

Preoperative pain mechanisms assessed by cuff algometry are associated with chronic postoperative pain relief after total knee replacement.

Chronic postoperative pain after total knee replacement (TKR) in knee osteoarthritis (KOA) implies clinical challenges. Widespread hyperalgesia, facilitated temporal summation of pain (TSP), and impaired conditioned pain modulation (CPM) have been found in painful KOA. This exploratory study investigated postoperative pain relief 12 months after TKR in 4 subgroups of patients preoperatively profiled by mechanistic quantitative sensory testing. In 103 patients with KOA, pressure pain detection threshold (PDT) and tolerance thresholds (PTT) were assessed at the lower leg using cuff algometry. Temporal summation of pain was measured as an increase in pain intensity scores during 10 repeated (2 seconds intervals) painful cuff stimuli. Conditioned pain modulation was calculated as the relative increase in PDT during painful conditioning stimulation. The grand averages of TSP and CPM were calculated and values below or above were used for subgrouping: facilitated TSP/impaired CPM (group A, N = 16), facilitated TSP/normal CPM (group B, N = 15), normal TSP/impaired CPM (group C, N = 44), and normal TSP/normal CPM (group D, N = 28). Clinical VAS pain intensity scores were collected before and 12 months after TKR surgery and the pain relief calculated. Less pain relief was found in group A (52.0% ± 14.0% pain relief) than in group B (81.1% ± 3.5%, P = 0.023) and group C (79.6% ± 4.4%, P = 0.007), but not group D (69.4% ± 7.9%, P = 0.087). Low preoperative PDT was associated with a less postoperative pain relief (R = -0.222, P = 0.034), whereas TSP or CPM alone showed no associations with postoperative pain relief. This explorative study indicated that patients with osteoarthritis with facilitated TSP together with impaired CPM are more vulnerable to experience less pain relief after TKR.

Open-Wedge High Tibial Osteotomy: RCT 2 Years RSA Follow-Up.

We investigated the influence of three different bone grafting materials on stability and clinical outcome of the healing open-wedge high tibial osteotomy (OW-HTO) with immediate partial weight bearing. A total of 45 (3 × 15) patients were randomized to injectable calcium phosphate cement (Calcibon; Biomet-Merck Biomaterials GmbH, Darmstadt, Germany), local bone autograft, or iliac crest autograft. Stability of the bony healing was evaluated with radiostereometric analysis (RSA) up to 24 months postoperatively. Clinical outcome was evaluated with the knee injury and osteoarthritis outcome score (KOOS). RSA revealed translations and rotations close to zero regardless of bone grafting material, with no statistically significant differences between the groups. Clinically, the Calcibon group had lower quality of life KOOS subscore at 2 years follow-up. We conclude that with a stable implant and 6 weeks of partial weight bearing, local autografting is sufficient to achieve solid bone consolidation following OW-HTO.

Analgesic and sedative effects of perioperative gabapentin in total knee arthroplasty: a randomized, double-blind, placebo-controlled dose-finding study.

Gabapentin has shown acute postoperative analgesic effects, but the optimal dose and procedure-specific benefits vs harm have not been clarified. In this randomized, double-blind, placebo-controlled dose-finding study, 300 opioid-naive patients scheduled for total knee arthroplasty were randomized (1:1:1) to either gabapentin 1300 mg/d (group A), gabapentin 900 mg/d (group B), or placebo (group C) daily from 2 hours preoperatively to postoperative day 6 in addition to a standardized multimodal analgesic regime. The primary outcome was pain upon ambulation 24 hours after surgery, and the secondary outcome was sedation 6 hours after surgery. Other outcomes were overall pain during well-defined mobilizations and at rest and sedation during the first 48 hours and from days 2-6, morphine use, anxiety, depression, sleep quality, and nausea, vomiting, dizziness, concentration difficulty, headache, visual disturbances, and adverse reactions. Pain upon ambulation (visual analog scale, mean [95% confidence interval]) 24 hours after surgery in group A vs B vs C was as follows: 41 [37-46] vs 41 [36-45] vs 42 [37-47], P = 0.93. Sedation (numeric rating scale, median [range]) 6 hours after surgery was as follows: 3.2 [0-10] vs 2.6 [0-9] vs 2.3 [0-9], the mean difference A vs C being 0.9 [0.2-1.7], P = 0.046. No between-group differences were observed in overall pain or morphine use the first 48 hours and from days 2-6. Sleep quality was better during the first 2 nights in group A and B vs C. Dizziness was more pronounced from days 2-6 in A vs C. More severe adverse reactions were observed in group A vs B and C. In conclusion, gabapentin may have a limited if any role in acute postoperative pain management of opioid-naive patients undergoing total knee arthroplasty and should not be recommended as a standard of care.

Presurgical assessment of temporal summation of pain predicts the development of chronic postoperative pain 12 months after total knee replacement.

Patients with knee osteoarthritis demonstrate decreased pressure pain thresholds (PPTs), facilitated temporal summation (TS) of pain, and decreased conditioned pain modulation (CPM) compared with healthy controls. This study aimed to correlate preoperative PPTs, TS, and CPM with the development of chronic postoperative pain after total knee replacement (TKR) surgery. Knee pain intensity (visual analog scale [VAS]: 0-10), PPTs, TS, and CPM were collected before, 2 months, and 12 months after TKR. Patients were divided into a low-pain (VAS < 3) and a high-pain (VAS ≥ 3) group based on their VAS 12 months after TKR. The high-pain group (N = 17) had higher pain intensities compared with the low-pain group (N = 61) before surgery (P = 0.009) and 12 months after surgery (P < 0.001). The PPTs of the low-pain groups were normalized for all measurement sites comparing presurgery with 12 months postsurgery (P < 0.05, contralateral arm: P = 0.059), which was not the case for the high-pain group. The low-pain group showed a functional inhibitory CPM preoperatively and 12 months postoperatively (P < 0.05), which was not found in the high-pain group. The high-pain group had higher facilitated TS preoperatively and 12 months postoperatively compared with the low-pain group (P < 0.05). Preoperative TS level correlated to 12-month postoperative VAS (R = 0.240, P = 0.037). Patients who developed moderate-to-severe pain had pronociceptive changes compared with patients who developed mild pain postsurgery. Preoperative TS level correlated with the postoperative pain intensity and may be a preoperative mechanistic predictor for the development of chronic postoperative pain in patients with osteoarthritis after TKR.

Efficacy of multimodal, systematic non-surgical treatment of knee osteoarthritis for patients not eligible for a total knee replacement: a study protocol of a randomised controlled trial.

INTRODUCTION: It is recommended that non-operative treatment of knee osteoarthritis (KOA) should be individually tailored and include multiple treatment modalities. Despite these recommendations, no one has yet investigated the efficacy of combining several non-surgical treatment modalities in a randomised controlled study. The purpose of this randomised controlled study is to examine if an optimised, combined non-surgical treatment programme results in greater improvements in pain, function and quality of life in comparison with usual care in patients with KOA who are not eligible for total knee arthroplasty (TKA). METHODS AND ANALYSIS: This study will include 100 consecutive patients from the North Denmark Region not eligible for TKA with radiographic KOA (K-L grade ≥1) and mean pain during the previous week of ≤60 mm (0-100). The participants will be randomised to receive either a 12-week non-surgical treatment programme consisting of patient education, exercise, diet, insoles, paracetamol and/or NSAIDs or usual care (two information leaflets containing information on KOA and advice regarding the above non-surgical treatment). The primary outcome will be the change from baseline to 12 months on the self-report questionnaire Knee Injury and Osteoarthritis Outcome Score (KOOS)(4) defined as the average score for the subscale scores for pain, symptoms, activities of daily living and quality of life. Secondary outcomes include the five individual KOOS subscale scores, pain on a 100 mm Visual Analogue Scale, EQ-5D, self-efficacy, pain pressure thresholds, postural control and isometric knee flexion and knee extension strength. ETHICS AND DISSEMINATION: This study was approved by the local Ethics Committee of The North Denmark Region (N-20110085) and the protocol conforms to the principles of the Declaration of Helsinki. Data collection will be completed by April 2014. Publications will be ready for submission in the summer of 2014. TRIAL REGISTRATION NUMBER: This study is registered with http://clinicaltrials.gov (NCT01535001).

[Clinical, radiological and arthroscopic graduation of knee osteoarthritis]. / Klinisk, radiologisk og artroskopisk graduering af knæartrose.

According to the American College of Rheumatology criteria, knee osteoarthritis can be diagnosed solely from clinical or radiological findings. The cardinal symptom is pain during activity or at rest. To score pain and functional deficits, several systems have been developed among which visual analogue scale for pain scoring and Western Ontario and McMaster Universities osteoarthritis index, Knee Injury and Osteoarthritis Outcome Scale or Oxford Knee Score for combined scoring of pain and function are the ones used most frequently. The severity of cartilage degradation is determined by X-ray and arthroscopy. There is still not consensus on magnetic resonance imaging criteria for the diagnosis and severity of knee osteoarthritis.

Comparison of trabecular metal cups and titanium fiber-mesh cups in primary hip arthroplasty: a randomized RSA and bone mineral densitometry study of 50 hips.

BACKGROUND: Trabecular metal has shown promising results in experimental studies of bone ingrowth. Several clinical studies support these results. However, until now, no randomized clinical radiostereometric analysis (RSA) studies have been published. In this randomized RSA trial, we compared a new acetabular cup with a surface made of tantalum trabecular metal and a cup with a titanium fiber-mesh surface. PATIENTS AND METHODS: Between 2004 and 2006, we operated 60 patients with noninflammatory hip arthritis. The patients were randomized to receive either an uncemented cup with a titanium fiber-mesh surface (Trilogy cup) or a cup with a trabecular tantalum surface (Monoblock cup). After 2 years, 50 patients had completed the study. The primary endpoint was cup migration within the first 2 years after surgery; the secondary endpoints were change in bone mineral density and Harris hip score at 3 months. RESULTS: Both cup types showed excellent fixation. RSA revealed minimal translation and rotation at 2 years. There was no statistically significant difference between the cup types with regard to translation. However, less rotation along the transverse axis was seen in the trabecular metal cups than in the fiber mesh cups: mean -0.01º (95% CI: -0.11 to 0.12) for trabecular metal cups and -0.60º (-0.72 to -0.48) for fiber-mesh cups (p = 0.04). The degree of periprosthetic bone loss was similar between the cup types in any of the regions of interest at 2 years of follow-up. 3 months postoperatively, we found a similar increase in Harris hip score in both groups: from around 50 to over 90. INTERPRETATION: We found promising early results concerning fixation of trabecular metal components to the acetabular host bone. However, we recommend a longer observation period to evaluate the outcome of this new cup design.

Differences in zinc status between patients with osteoarthritis and osteoporosis.

Zinc has been suggested to play an important role in the development of osteoporosis, whereas the influence of zinc on osteoarthritis has attracted much less attention. The aim of the study was to investigate and compare the zinc status and bone turnover, density, and biomechanical properties of osteoarthritic and osteoporotic patients. The study comprised 40 women who underwent hip replacement due to osteoarthritis or osteoporosis. Serum and urine zinc content, and bone resorption markers and serum bone formation markers were determined. The unaffected hip and the exarticulated affected femoral head underwent DEXA scanning. Bone biopsies were obtained from the femoral heads and the biomechanical properties were determined. The biopsies were ashed and the bone zinc content was ascertained. Osteoarthritic patients had significantly higher serum zinc concentrations and lower urine zinc concentrations than osteoporotic patients, whereas the bone zinc content did not differ. The zinc status was not found to be a predictor for the bone strength. In conclusion, the finding that the zinc status of osteoporotic patients is significantly different from that of osteoartritic patients is new and supports the view that osteoporosis and osteoarthritis rarely occur in the same individual.