Radiographic morphometry and densitometry predict strength of cadaveric proximal humeri more reliably than age and DXA scan density

Methods are needed for identifying poorer quality cadaver proximal humeri to ensure that they are not disproportionately segregated into experimental groups for fracture studies. We hypothesized that measurements made from radiographs of cadaveric proximal humeri are stronger predictors of fracture strength than chronological age or bone density values derived from dual-energy x-ray absorptiometry (DXA) scans. Thirty-three proximal humeri (range: 39-78 years) were analyzed for: (1) bone mineral density (BMD, g/cm(2)) using DXA, (2) bulk density (g/cm(3)) using DXA and volume displacement, (3) regional bone density in millimeters of aluminum (mmAl) using radiographs, and (4) regional mean (medial+lateral) cortical thickness and cortical index (CI) using radiographs. The bones were then fractured simulating a fall. Strongest correlations with ultimate fracture load (UFL) were: mean cortical thickness at two diaphyseal locations (r = 0.71; p < 0.001), and mean mmAl in the humeral head (r = 0.70; p < 0.001). Weaker correlations were found between UFL and DXA-BMD (r = 0.60), bulk density (r = 0.43), CI (r = 0.61), and age (r = -0.65) (p values <0.01). Analyses between UFL and the product of any two characteristics showed six combinations with r-values >0.80, but none included DXA-derived density, CI, or age. Radiographic morphometric and densitometric measurements from radiographs are therefore stronger predictors of UFL than age, CI, or DXA-derived density measurements.

Reusing cadaveric humeri for fracture testing after testing simulated rotator cuff tendon repairs

The financial cost of using human tissues in biomedical testing and surgical reconstruction is predicted to increase at a rate that is disproportionately greater than other materials used in biomechanical testing. Our first hypothesis is that cadaveric proximal humeri that had undergone monotonic failure testing of simulated rotator cuff repairs would not differ in ultimate fracture loads or in energy absorbed to fracture when compared to controls (i.e., bones without cuff repairs). Our second hypothesis is that there can be substantial cost savings if these cadaveric proximal humeri, with simulated cuff repairs, can be re-used for fracture testing. Results of fracture tests (conducted in a backwards fall configuration) and cost analysis support both hypotheses. Hence, the bones that had undergone monotonic failure tests of various rotator cuff repair techniques can be re-used in fracture tests because their load-carrying capacity is not significantly reduced.

A novel double-row rotator cuff repair exceeds strengths of conventional repairs

Double-row rotator cuff repairs are becoming popular because of their ability to improve initial ultimate failure load for full-thickness rotator cuff tears, especially in middle-aged to elderly patients. We hypothesized a quasi-double-row repair using a combination of transosseous sutures, anchors, and double knots (TOAK technique) would exceed the clinically relevant 250-N load threshold and the initial mean ultimate failure loads of anchor-only and transosseous suture-only fixation. In simulated full-thickness supraspinatus tears in cadavers (mean age, 62 years; range, 50-77 years), failure loads of two repair techniques were compared with a TOAK repair using sutures and bioabsorbable anchors. Radiographic densitometry was conducted on all humeral heads. Testing was performed at 6 mm per minute in 18 bones in the following three groups (n = 6 per group): (1) transosseous suture-only with weave-type stitch and single-knot fixation; (2) anchor-only with horizontal mattress stitch and single-knot fixation; and (3) TOAK. The mean ultimate failure load was 238 N for the transosseous suture-only group and 215 N for the anchor-only group. Although the bones had lower density, TOAK specimens failed at 55% to 67% higher loads (mean, 404 N) than the other groups. These data support further evaluation of the TOAK technique for full-thickness supraspinatus tears in middle-aged to elderly patients.

Variations in corticosteroid/anesthetic injections for painful shoulder conditions: comparisons among orthopaedic surgeons, rheumatologists, and physical medicine and primary-care physicians

Background

Variations in corticosteroid/anesthetic doses for injecting shoulder conditions were examined among orthopaedic surgeons, rheumatologists, and primary-care sports medicine (PCSMs) and physical medicine and rehabilitation (PMRs) physicians to provide data needed for documenting inter-group differences for establishing uniform injection guidelines.

Methods

264 surveys, sent to these physicians in our tri-state area of the western United States, addressed corticosteroid/anesthetic doses and types used for subacromial impingement, degenerative glenohumeral and acromioclavicular arthritis, biceps tendinitis, and peri-scapular trigger points. They were asked about preferences regarding: 1) fluorinated vs. non-fluorinated corticosteroids, 2) acetate vs. phosphate types, 3) patient age, and 4) adjustments for special considerations including young athletes and diabetics.

Results

169 (64% response rate, RR) surveys were returned: 105/163 orthopaedic surgeons (64%RR), 44/77 PCSMs/PMRs (57%RR), 20/24 rheumatologists (83%RR). Although corticosteroid doses do not differ significantly between specialties (p > 0.3), anesthetic volumes show broad variations, with surgeons using larger volumes. Although 29% of PCSMs/PMRs, 44% rheumatologists, and 41% surgeons exceed "recommended" doses for the acromioclavicular joint, >98% were within recommendations for the subacromial bursa and glenohumeral joint. Depo-Medrol^® (methylprednisolone acetate) and Kenalog^® (triamcinolone acetonide) are most commonly used. More rheumatologists (80%) were aware that there are acetate and phosphate types of corticosteroids as compared to PCSMs/PMRs (76%) and orthopaedists (60%). However, relatively fewer rheumatologists (25%) than PCSMs/PMRs (32%) or orthopaedists (32%) knew that phosphate types are more soluble. Fluorinated corticosteroids, which can be deleterious to soft tissues, were used with these frequencies for the biceps sheath: 17% rheumatologists, 8% PCSMs/PMRs, 37% orthopaedists. Nearly 85% use the same non-fluorinated corticosteroid for all injections; <10% make adjustments for diabetic patients.

Conclusion

Variations between specialists in anesthetic doses suggest that surgeons (who use significantly larger volumes) emphasize determining the percentage of pain attributable to the injected region. Alternatively, this might reflect a more profound knowledge that non-surgeons specialists have of the potentially adverse cardiovascular effects of these agents. Variations between these specialists in corticosteroid/anesthetic doses and/or types, and their use in some special situations (e.g., diabetics), bespeak the need for additional investigations aimed at establishing uniform injection guidelines, and for identifying knowledge deficiencies that warrant advanced education.

Temporal variations in a modified Neer impingement test can confound clinical interpretation

High variability in the time required for patients to have substantial pain relief after Neer-type subacromial impingement tests might help explain conflicting data regarding their effectiveness in guiding treatment and predicting surgical outcomes. To focus on quantifying temporal variability associated with a modified (local anesthetic and corticosteroid) impingement test, we hypothesized that substantial pain relief (greater than 75% reduction) can occur beyond the 10-minute interval many clinicians use for determining results of this test. Fourteen females and 12 males (mean age, 55.6 years) who received subacromial injections for Stage II impingement completed 10-cm visual analog scales for pain at 5, 10, 20, 30, and 40 minutes postinjection. There were 11 patients (42%) who attained at least 75% relief by 10 minutes compared with nine (35%) additional patients who subsequently attained 75% relief after 10 minutes. On average, 75% reduction in pain did not occur until after 30 minutes postinjection. Data analysis also revealed two groups: (1) rapid responders with greater than 50% pain relief by 10 minutes; and (2) delayed responders with greater than 50% pain relief after 10 minutes. Assessing pain at 10 minutes for a Neer-type impingement test can fail to accurately determine a positive test in a substantial percentage of patients.

Knowledge and opinions of orthopaedic surgeons concerning medical evaluation and treatment of patients with osteoporotic fracture

BACKGROUND

With the exponential increase in osteoporotic fractures, orthopaedic surgeons are in a logical position to become more involved in the medical treatment of this disease. However, it has been hypothesized that surgeons may not be inclined to initiate such treatment if they do not view medical interventions as an extension of their surgical opportunities. The objective of this study was to determine the knowledge and opinions of orthopaedic surgeons with regard to their opportunities for initiating medical treatment of patients with an osteoporotic fracture.

METHODS

A survey consisting of twenty-two questions was administered to 171 orthopaedic surgeons in Utah, Idaho, and Wyoming.

RESULTS

Of the 171 surveys that were mailed, 107 usable surveys were returned (a 63% response rate). A majority of the orthopaedic surgeons thought that it was appropriate to expand their orthopaedic practice to include prescribing pharmacological treatments for osteoporosis (68% agreed or strongly agreed with that statement). However, 47% were concerned enough about adverse events related to some conventional pharmacological treatments that they would rather avoid prescribing them. Of the surgeons who were willing to prescribe these treatments, 74% felt most comfortable prescribing bisphosphonates and >77% felt most comfortable prescribing calcium and vitamin-D supplements. Fifty-one percent considered an apparent osteoporotic fracture and several other clinical risk factors for osteoporosis as sufficient evidence for initiating pharmacological treatments, whereas 72% thought that a bone-density scan should be made before initiating treatment. Although 32% thought that all nonoperative treatment should be the responsibility of a primary care provider, 63% thought that the orthopaedic surgeon should initiate a workup to look for secondary causes of the osteoporosis and should begin medical treatment of patients with an osteoporotic fracture before referring them.

CONCLUSIONS

Although a majority of orthopaedic surgeons believe that they should expand their role in the medical treatment of patients with an osteoporotic fracture, many do not institute medical treatment and think that the patient's primary care providers should be responsible for medical care.