Prevalence and Risk Factors of Spine,Shoulder, Hand,Hip, and Knee Osteoarthritis in Community-dwelling Koreans Older Than Age 65 Years

Background

Osteoarthritis (OA) is common and disabling among older patients around the world. Data exploring the prevalence and risk factors of OA are of paramount importance in establishing healthcare policies. However, few studies have evaluated these topics among Asian populations.

Questions/purposes

This study was conducted to determine the prevalence and risk factors of radiographic OA in the spine, shoulder, hand, hip, and knee in Koreans older than age 65 years.

Methods

A simple random sample (N = 1118) was drawn from a roster of elderly individuals older than age 65 years in Seongnam. Of the 1118 invited subjects, 696 (males = 298, females = 398) participated in this study (a response rate of 62%). The mean age of respondents was 72 ± 5 years (range, 65–91 years). Radiographs of the lumbar spine, shoulder, hand, hip, and knee were taken and afterward evaluated for radiographic OA. The Kellgren-Lawrence grading system was used for all mentioned joints, and radiographic OA was defined as Grade 2 changes or higher. The association of sex, aging, and obesity with OA in each of the mentioned joints was determined with the help of multivariate logistic regression.

Results

The highest prevalence of radiographic OA was seen in the spine (number of subjects with OA/number of whole population = 462 of 696 [66%]) followed by the hand (415 of 692 [60%]), knee (265 of 696 [38%]), shoulder (36 of 696 [5%]), and hip (15 of 686 [2%]). Female sex was associated with knee OA (odds ratio [OR], 5.7; 95% confidence interval [CI], 3.9–8.4; p < 0.001) and hand OA (OR, 2.3; 95% CI, 1.6–3.1; p < 0.001), and male sex was associated with spine OA (OR, 0.7; 95% CI, 0.5–1.0; p = 0.025). Aging was associated with radiographic OA in the spine, knee, and hand (OR per 5-year increments, 1.3 [95% CI, 1.1–1.6; p = 0.001], 1.6 [95% CI, 1.4–1.9; p < 0.001], and 1.4 [95% CI, 1.2–1.7; p < 0.001]), respectively) but not associated with OA in the hip and shoulder. Obesity was associated with knee OA (OR, 3.4; 95% CI, 2.4–5.0; p < 0.001) and spine OA (OR, 1.5; 95% CI, 1.1–2.2; p = 0.014) but not with OA in other joints.

Conclusions

OA of the spine, hand, and knee is likely to become a major public health problem rather than shoulder and hip OA in Korea. Associations of demographic factors with radiographic OA differed among each joint, and that would be valuable information to assess the role and influence of risk factors of OA in various joints.

Level of Evidence

Level III, prognostic study.     

Does Native Combined Anteversion Influence Pain Onset in Patients With Dysplastic Hips?

Background

Combined anteversion is the sum of femoral and acetabular anteversion and represents their morphological relationship in the axial plane. Few studies have investigated the native combined anteversion in patients with symptomatic dysplastic hips.

Questions/purposes

We hypothesized the following: (1) dysplastic hips have two distinct populations, which differ from each other and from normal hips in their combined anteversion; and (2) these populations differ clinically in terms of correlation between age of onset of symptoms and amount of anteversion.

Methods

We measured radiographic parameters by CT of 100 dysplastic hips in 76 patients who were symptomatic enough to undergo periacetabular osteotomy and of 50 normal hips in 44 patients who had CT scans as part of preparation for computer-navigated TKAs; these patients had no visible hip arthritis or dysplasia and no hip symptoms. Dysplastic hips were divided into the anteversion (83 hips) and retroversion groups (17 hips) based on acetabular version. Age at pain onset was determined from their medical charts.

Results

Combined anteversion in the anteversion group was greater than that in the retroversion and control groups: 47° ± 12°, 30° ± 16°, and 36° ± 9°, respectively. In the anteversion group, combined anteversion (r = −0.49; 95% confidence interval [CI], −0.66 to −0.27; p < 0.001) and femoral anteversion (r = −0.41; 95% CI, −0.60 to −0.19; p < 0.001) were associated with an earlier age at pain onset; however, no such relationships were observed in the retroversion group. After controlling for relevant potential confounding variables, we found that combined anteversion (hazard ratio [HR], 1.04; 95% CI, 1.01–1.07; p = 0.006) and Sharp angle (HR, 1.10; 95% CI, 1.02–1.17; p = 0.008) were associated with an earlier age of pain onset in the anteversion group.

Conclusions

These results suggest that not only lateral coverage of the femoral head, but also axial joint morphology is important for the development of pain in the anteversion group. Optimal combined anteversion should be considered during periacetabular osteotomy.

Level of Evidence

Level IV, prognostic study.     

Risk Calculators Predict Failures of Knee and Hip Arthroplasties: Findings from a Large Health Maintenance Organization

Background

Considering the cost and risk associated with revision Total knee arthroplasty (TKAs) and Total hip arthroplasty (THAs), steps to prevent these operations will help patients and reduce healthcare costs. Revision risk calculators for patients may reduce revision surgery by supporting clinical decision-making at the point of care.

Questions/purposes

We sought to develop a TKA and THA revision risk calculator using data from a large health-maintenance organization’s arthroplasty registry and determine the best set of predictors for the revision risk calculator.

Methods

Revision risk calculators for THAs and TKAs were developed using a patient cohort from a total joint replacement registry and data from a large US integrated healthcare system. The cohort included all patients who had primary procedures performed in our healthcare system between April 2001 and July 2008 and were followed until January 2014 (TKAs, n = 41,750; THAs, n = 22,721), During the study period, 9% of patients (TKA = 3066/34,686; THA=1898/20,285) were lost to followup and 7% died (TKA= 2350/41,750; THA=1419/20,285). The outcome of interest was revision surgery and was defined as replacement of any component for any reason within 5 years postoperatively. Candidate predictors for the revision risk calculator were limited to preoperative patient demographics, comorbidities, and procedure diagnoses. Logistic regression models were used to identify predictors and the Hosmer-Lemeshow goodness-of-fit test and c-statistic were used to choose final models for the revision risk calculator.

Results

The best predictors for the TKA revision risk calculator were age (odds ratio [OR], 0.96; 95% CI, 0.95–0.97; p < 0.001), sex (OR, 0.84; 95% CI, 0.75–0.95; p = 0.004), square-root BMI (OR, 1.05; 95% CI, 0.99–1.11; p = 0.140), diabetes (OR, 1.32; 95% CI, 1.17–1.48; p < 0.001), osteoarthritis (OR, 1.16; 95% CI, 0.84–1.62; p = 0.368), posttraumatic arthritis (OR, 1.66; 95% CI, 1.07–2.56; p = 0.022), and osteonecrosis (OR, 2.54; 95% CI, 1.31–4.92; p = 0.006). The best predictors for the THA revision risk calculator were sex (OR, 1.24; 95% CI, 1.05–1.46; p = 0.010), age (OR, 0.98; 95% CI, 0.98–0.99; p < 0.001), square-root BMI (OR, 1.07; 95% CI, 1.00–1.15; p = 0.066), and osteoarthritis (OR, 0.85; 95% CI, 0.66–1.09; p = 0.190).

Conclusions

Study model parameters can be used to create web-based calculators. Surgeons can enter personalized patient data in the risk calculators for identification of risk of revision which can be used for clinical decision making at the point of care. Future prospective studies will be needed to validate these calculators and to refine them with time.

Level of Evidence

Level III, prognostic study.     

Low Albumin Levels,More Than Morbid Obesity,Are Associated With Complications After TKA

Background

Morbid obesity and malnutrition are thought to be associated with more frequent perioperative complications after TKA. However, morbid obesity and malnutrition often are co-occurring conditions. Therefore it is important to understand whether morbid obesity, malnutrition, or both are independently associated with more frequent perioperative complications. In addition, assessing the magnitude of an increase in complications and whether these complications are major or minor is important for both conditions.

Questions/purposes

We asked: (1) Is morbid obesity independently associated with more frequent major perioperative complications after TKA? (2) Are major perioperative complications after TKA more prevalent among patients with a low serum albumin?

Methods

The National Surgical Quality Improvement Program (NSQIP) database was analyzed from 2006 to 2013. Patients were grouped as morbidly obese (BMI ≥ 40 kg/m²) or nonmorbidly obese (BMI ≥ 18.5 kg/m² to < 40 kg/m²), or by low serum albumin (serum albumin level < 3.5 mg/dL) or normal serum albumin (serum albumin level ≥ 3.5 mg/dL). The study cohort included 77,785 patients, including 35,573 patients with a serum albumin level of 3.5 g/dL or greater and 1570 patients with a serum albumin level less than 3.5 g/dL. Therefore, serum albumin levels were available for only 37,173 of the 77,785 of the patients (48%). There were 66,382 patients with a BMI between 18.5 kg/m² and 40 kg/m² and 11,403 patients with a BMI greater than 40 kg/m². Data were recorded on patient mortality along with 21 complications reported in the NSQIP. We also developed three composite complication variables to represent risk of any infections, cardiac or pulmonary complications, and any major complications. For each complication, multivariate logistic regression analysis was performed. Independent variables included patient age, sex, race, BMI, American Society of Anesthesiologists classification, year of surgery, and Charlson comorbidity index score.

Results

Mortality was not increased in the morbidly obese group (0.14% vs 0.14%; p = 0.942). Patients who were morbidly obese were more likely to have progressive renal insufficiency (0.30% vs 0.10%; odds ratio [OR], 2.47; 95% CI, 1.27–4.29; p < 0.001), superficial infection (1.07% vs 0.55%; OR, 1.87; 95% CI, 1.39–2.51; p < 0.001), and sepsis (0.36% vs 0.23%; OR, 1.70; 95% CI, 1.04–2.53; p = 0.034) compared with patients who were not morbidly obese. Patients who were morbidly obese were less likely to require blood transfusion (8.68% vs 12.06%; OR, 0.70; 95% CI, 0.63–0.77; p < 0.001) compared with patients who were not morbidly obese. Morbid obesity was not associated with any of the other 21 perioperative complications recorded in the NSQIP database. With respect to the composite complication variables, patients who were morbidly obese had an increased risk of any infection (3.31% vs 2.41%; OR, 1.38; 95% CI, 1.16–1.64; p < 0.001) but not for cardiopulmonary or any major complication. The group with low serum albumin had higher mortality than the group with normal serum albumin (0.64% vs 0.15%; OR, 3.17; 95% CI, 1.58–6.35; p = 0.001). Patients in the low serum albumin group were more likely to have a superficial surgical site infection (1.27% vs 0.64%; OR, 1.27; 95% CI, 1.09–2.75; p = 0.020); deep surgical site infection (0.38% vs 0.12%; OR, 3.64; 95% CI, 1.54–8.63; p = 0.003); organ space surgical site infection (0.45% vs 0.15%; OR, 2.71; 95% CI, 1.23–5.97; p = 0.013); pneumonia (1.21 vs 0.29%; OR, 3.55; 95% CI, 2.14–5.89; p < 0.001); require unplanned intubation (0.51% vs 0.17%, OR, 2.24; 95% CI, 1.07–4.69; p = 0.033); and remain on a ventilator more than 48 hours (0.38% vs 0.07%; OR, 4.03; 95% CI, 1.64–9.90; p = 0.002). They are more likely to have progressive renal insufficiency (0.45 % vs 0.12%; OR, 2.71; 95% CI, 1.21–6.07; p = 0.015); acute renal failure (0.32% vs 0.06%; OR, 5.19; 95% CI, 1.96–13.73; p = 0.001); cardiac arrest requiring cardiopulmonary resuscitation (0.19 % vs 0.12%; OR, 3.74; 95% CI, 1.50–9.28; p = 0.005); and septic shock (0.38% vs 0.08%; OR, 4.4; 95% CI, 1.74–11.09; p = 0.002). Patients in the low serum albumin group also were more likely to require blood transfusion (17.8% vs 12.4%; OR, 1.56; 95% CI, 1.35–1.81; p < 0.001). In addition, among the three composite complication variables, any infection (5.0% vs 2.4%; OR, 2.0; 95% CI, 1.53–2.61; p < 0.001) and any major complication (2.4% vs 1.3%; OR, 1.41; 95% CI, 1.00–1.97; p = 0.050) were more prevalent among the patients with low serum albumin. There was no difference for cardiopulmonary complications.

Conclusions

Morbid obesity is not independently associated with the majority of perioperative complications measured by the NSQIP and was associated only with increases in progressive renal insufficiency, superficial surgical site infection, and sepsis among the 21 perioperative variables measured. However, low serum albumin was associated with increased mortality and multiple additional major perioperative complications after TKA. Low serum albumin, more so than morbid obesity, is associated with major perioperative complications. This is an important finding, as low serum albumin may be more modifiable than morbid obesity in patients who are immobile or have advanced knee osteoarthritis.

Level of Evidence

Level III, prognostic study.     

How Do Different Anterior Tibial Tendon Transfer Techniques Influence Forefoot and Hindfoot Motion?

Background

Idiopathic clubfoot correction is commonly performed using the Ponseti method and is widely reported to provide reliable results. However, a relapsed deformity may occur and often is treated in children older than 2.5 years with repeat casting, followed by an anterior tibial tendon transfer. Several techniques have been described, including a whole tendon transfer using a two-incision technique or a three-incision technique, and a split transfer, but little is known regarding the biomechanical effects of these transfers on forefoot and hindfoot motion.

Questions/purpose

We used a cadaveric foot model to test the effects of three tibialis anterior tendon transfer techniques on forefoot positioning and production of hindfoot valgus.

Methods

Ten fresh-frozen cadaveric lower legs were used. We applied 150 N tension to the anterior tibial tendon, causing the ankle to dorsiflex. Three-dimensional motions of the first metatarsal, calcaneus, and talus relative to the tibia were measured in intact specimens, and then repeated after each of the three surgical techniques.

Results

Under maximum dorsiflexion, the intact specimens showed 6° (95% CI, 2.2°–9.4°) forefoot supination and less than 3° (95% CI, 0.4°–5.3°) hindfoot valgus motion. All three transfers provided increased forefoot pronation and hindfoot valgus motion compared with intact specimens: the three-incision whole transfer provided 38° (95% CI, 33°–43°; p < 0.01) forefoot pronation and 10° (95% CI, 8.5°–12°; p < 0.01) hindfoot valgus; the split transfer, 28° (95% CI, 24°–32°; p < 0.01) pronation, 9° (95% CI, 7.5°–11°; p < 0.01) valgus; and the two-incision transfer, 25° (95% CI, 20°–31°; p < 0.01) pronation, 6° (95% CI, 4.2°–7.8°; p < 0.01) valgus.

Conclusion

All three techniques may be useful and deliver varying degrees of increased forefoot pronation, with the three-incision whole transfer providing the most forefoot pronation. Changes in hindfoot motion were small.

Clinical Relevance

Our study results show that the amount of forefoot pronation varied for different transfer methods. Supple dynamic forefoot supination may be treated with a whole transfer using a two-incision technique to avoid overcorrection, while a three-incision technique or a split transfer may be useful for more resistant feet. Confirmation of these findings awaits further clinical trials.     

An Increased Iliocapsularis-to-rectus-femoris Ratio Is Suggestive for Instability in Borderline Hips

Background

The iliocapsularis muscle is an anterior hip structure that appears to function as a stabilizer in normal hips. Previous studies have shown that the iliocapsularis is hypertrophied in developmental dysplasia of the hip (DDH). An easy MR-based measurement of the ratio of the size of the iliocapsularis to that of adjacent anatomical structures such as the rectus femoris muscle might be helpful in everyday clinical use.

Questions/purposes

We asked (1) whether the iliocapsularis-to-rectus-femoris ratio for cross-sectional area, thickness, width, and circumference is increased in DDH when compared with hips with acetabular overcoverage or normal hips; and (2) what is the diagnostic performance of these ratios to distinguish dysplastic from pincer hips?

Methods

We retrospectively compared the anatomy of the iliocapsularis muscle between two study groups with symptomatic hips with different acetabular coverage and a control group with asymptomatic hips. The study groups were selected from a series of patients seen at the outpatient clinic for DDH or femoroacetabular impingement. The allocation to a study group was based on conventional radiographs: the dysplasia group was defined by a lateral center-edge (LCE) angle of < 25° with a minimal acetabular index of 14° and consisted of 45 patients (45 hips); the pincer group was defined by an LCE angle exceeding 39° and consisted of 37 patients (40 hips). The control group consisted of 30 asymptomatic hips (26 patients) with MRIs performed for nonorthopaedic reasons. The anatomy of the iliocapsularis and rectus femoris muscle was evaluated using MR arthrography of the hip and the following parameters: cross-sectional area, thickness, width, and circumference. The iliocapsularis-to-rectus-femoris ratio of these four anatomical parameters was then compared between the two study groups and the control group. The diagnostic performance of these ratios to distinguish dysplasia from protrusio was evaluated by calculating receiver operating characteristic (ROC) curves and the positive predictive value (PPV) for a ratio > 1. Presence and absence of DDH (ground truth) were determined on plain radiographs using the previously mentioned radiographic parameters. Evaluation of radiographs and MRIs was performed in a blinded fashion. The PPV was chosen because it indicates how likely a hip is dysplastic if the iliocapsularis-to-rectus-femoris ratio was > 1.

Results

The iliocapsularis-to-rectus-femoris ratio for cross-sectional area, thickness, width, and circumference was increased in hips with radiographic evidence of DDH (ratios ranging from 1.31 to 1.35) compared with pincer (ratios ranging from 0.71 to 0.90; p < 0.001) and compared with the control group, the ratio of cross-sectional area, thickness, width, and circumference was increased (ratios ranging from 1.10 to 1.15; p ranging from 0.002 to 0.039). The area under the ROC curve ranged from 0.781 to 0.852. For a one-to-one iliocapsularis-to-rectus-femoris ratio, the PPV was 89% (95% confidence interval [CI], 73%–96%) for cross-sectional area, 77% (95% CI, 61%–88%) for thickness, 83% (95% CI, 67%–92%) for width, and 82% (95% CI, 67%–91%) for circumference.

Conclusions

The iliocapsularis-to-rectus-femoris ratio seems to be a valuable secondary sign of DDH. This parameter can be used as an adjunct for clinical decision-making in hips with borderline hip dysplasia and a concomitant cam-type deformity to identify the predominant pathology. Future studies will need to prove this finding can help clinicians determine whether the borderline dysplasia accounts for the hip symptoms with which the patient presents.

Level of Evidence

Level III, prognostic study.     

Incidence and Risk Factors of Allograft Bone Failure After Calcaneal Lengthening

Background

Calcaneal lengthening with allograft is frequently used for the treatment of patients with symptomatic planovalgus deformity; however, the behavior of allograft bone after calcaneal lengthening and the risk factors for graft failure are not well documented.

Questions/purposes

(1) What proportion of the patients treated with allograft bone had radiographic evidence of graft failure and what further procedures were performed? (2) What are the risk factors for radiographic graft failure after calcaneal lengthening? (3) What patient factors are associated with the magnitude of correction achieved after calcaneal lengthening?

Methods

Between May 2003 and January 2014, we performed 341 calcaneal lengthenings on 202 patients for planovalgus deformity, the etiology of which included idiopathic, cerebral palsy, and other neuromuscular disease. Of these, 176 patients (87%) had adequate followup for graft evaluation, defined as lateral radiographs taken before and at least 6 months after the index procedure (mean, 18 months; range, 6–100 months) and 117 patients (58%) had adequate followup for the assessment of the extent of correction, defined as weightbearing anteroposterior and lateral radiographs taken before and at least 1 year after the index procedure (mean, 24 months; range, 12–96 months). These patients’ results were evaluated retrospectively. The Goldberg scoring system was chosen for demonstration of allograft behavior. A score lower than 6 at 6 months after surgery was defined as radiographic graft failure; the highest possible score was 7 points, and this represented graft incorporation with excellent reorganization of the graft and no loss of height. The patient age, sex, diagnosis, graft material, ambulatory status, and use of antiseizure medication were evaluated as possible risk factors, and we controlled for the interaction of potentially confounding variables using multivariate analysis. Additionally, six radiographic indices were analyzed for their effects on the extent of correction.

Results

The mean estimated Goldberg score was 6 (SD, 1.14) at 6 months after calcaneal lengthening with 11 feet (4%) classified as radiographic graft failure (Goldberg score < 6). Of these, four feet (1%) underwent reoperation using an iliac autograft bone resulting from pain and loss of correction. Multivariate analysis showed that the tricortical iliac crest allograft was superior to the patellar allograft (odds ratio [OR], 3.2; 95% confidence interval [CI], 1.1–9.8; p = 0.038) and the possibility of radiographic graft failure was found to increase along with age (OR, 1.2; 95% CI, 1.0–1.3; p = 0.006). Radiographically, the extent of correction was found to decrease with patient age, as observed at the anteroposterior talus-first metatarsal angle (p < 0.001), lateral talocalcaneal angle (p < 0.001), lateral talus-first metatarsal angle (p < 0.001), and relative calcaneal length (p = 0.041).

Conclusions

Graft failure can occur after calcaneal lengthening using allograft. Our study showed that the tricortical iliac allograft was superior to the patellar allograft, and further studies are warranted to further elucidate the effects of age on radiographic graft failure.

Level of Evidence

Level III, therapeutic study.     

Caution Should be Taken in Performing Surgical Hip Dislocation for the Treatment of Femoroacetabular Impingement in Patients Over the Age of 40

Background

Open and arthroscopic procedures are treatment options for patients with femoroacetabular impingement (FAI). Age has been found to be a predictive factor in the outcome of patients undergoing periacetabular osteotomy (PAO) for hip dysplasia. It is unclear if older age contraindicates joint preservation through a surgical hip dislocation (SHD).

Questions/Purpose

The purpose of this retrospective case series was to evaluate the short-term outcomes of patients over 40 years of age without radiographic evidence of end-stage arthritis who underwent SHD for the treatment of FAI and to determine whether older age should be a contraindication for joint-preserving procedures in these patients. Our specific aims included (1) documenting the intraoperative findings and procedures, (2) assessing pain relief provided, and (3) assessing treatment failures and postoperative complications, noting the number of patients that ultimately required total hip arthroplasty (THA).

Patients and Methods

All patients at age 40 and older who had SHD for the treatment of FAI were identified from a series of patients treated with SHD. Clinical notes, radiographs, and operative reports were reviewed to determine clinical results, complications, and the need for additional procedures. The minimum follow-up was 1 year (mean 3.9 years; range 1–8 years).

Results

At final follow-up, 11/22 (50%) of hips had pain relief, while 11/22 (50%) either continued having significant symptoms or required THA. Five (23%) reported nontrochanteric pain symptoms that were the same or worse than before surgery, and six hips (27%) underwent subsequent THA). The average time between SHD and THA was 1.9 years (0.9–6.2). The average age of patients who went on to require THA was 45 (42–50) years.

Conclusions

Surgical hip dislocation can be used for the treatment of FAI in patients over age 40, but strict selection criteria should be adhered to, as only half of the patients experienced significant improvement in their hip pain. THA was required in one-third of hips for continued pain and radiographic progression of arthritis. SHD for treatment of pathology that is not amenable to hip arthroscopy should remain a surgical option in older patients with FAI only if joint degeneration is not present.     

Does Radiographic Coxa Profunda Indicate Increased Acetabular Coverage or Depth in Hip Dysplasia?

Background

Although radiographic coxa profunda has been considered an indicator of acetabular overcoverage, recent studies suggest that radiographic coxa profunda is a nonspecific finding seen even in hip dysplasia. The morphologic features of coxa profunda in hip dysplasia and the frequency with which the two overlap are not well defined.

Questions/purposes

We determined (1) the prevalence of radiographic coxa profunda in patients with hip dysplasia; (2) the morphologic differences of the acetabulum and pelvis between patients with hip dysplasia and control subjects; and (3) the morphologic differences between hip dysplasia with and without coxa profunda.

Methods

We retrospectively reviewed the pelvic radiographs and CT scans of 70 patients (70 hips) with hip dysplasia. Forty normal hips were used as controls. Normal hips were defined as those with a lateral center-edge angle between 25° and 40°. Coxa profunda was defined as present when the acetabular fossa was observed to touch or was medial to the ilioischial line on an AP pelvic radiograph. CT measurements included acetabular version, acetabular coverage, acetabular depth, and rotational alignment of the innominate bone.

Results

The prevalence of coxa profunda was 44% (31 of 70 hips) in dysplastic hips and 73% (29 of 40 hips) in the control hips (odds ratio, 3.32; 95% CI, 1.43–7.68). Dysplastic hips had a more anteverted and globally shallow acetabulum with inwardly rotated innominate bone compared with the control hips (p < 0.001). Dysplastic hips with coxa profunda had a more anteverted acetabulum (p < 0.001) and inwardly rotated innominate bone (p < 0.002) compared with those without coxa profunda, whereas the acetabular coverage and depth did not differ between the two groups, with the numbers available.

Conclusions

Radiographic coxa profunda was not a sign of increased acetabular coverage and depth in patients with hip dysplasia, but rather indicates classic acetabular dysplasia, defined by an anteverted acetabulum with anterolateral acetabular deficiency and an inwardly rotated pelvis. Thus, the presence of coxa profunda does not indicate a disease in addition to hip dysplasia, and the conventional maneuvers during periacetabular osteotomy are adequate for these patients.

Level of Evidence

Level IV, diagnostic study.     

What Middle Phalanx Base Fracture Characteristics are Most Reliable and Useful for Surgical Decision-making?

Background

Fracture-dislocations of the proximal interphalangeal joint are vexing because subluxation and articular damage can lead to arthrosis and the treatments are imperfect. Ideally, a surgeon could advise a patient, based on radiographs, when the risk of problems merits operative intervention, but it is unclear if middle phalanx base fracture characteristics are sufficiently reliable to be useful for surgical decision making.

Questions/purposes

We evaluated (1) the degree of interobserver agreement as a function of fracture characteristics, (2) the differences in interobserver agreement between experienced and less-experienced hand surgeons, and (3) what fracture characteristics and surgeon characteristics were associated with the decision for operative treatment.

Methods

Ninety-nine (33%) of 296 hand surgeons evaluated 21 intraarticular middle phalanx base fractures on lateral radiographs. Eighty-one surgeons (82%) were in academic practice and 57 (58%) had less than 10 years experience. Participants assessed six fracture characteristics and recommended treatment (nonoperative or operative: extension block pinning, external fixation, open reduction and internal fixation, volar plate arthroplasty, or hemihamate autograft arthroplasty) for all cases.

Results

With all surgeons pooled together, the interobserver agreement for fracture characteristics was substantial for assessment of a 2-mm articular step or gap (kappa, 0.73; 95% CI, 0.60–0.86; p < 0.001), subluxation or dislocation (kappa, 0.72; 95% CI, 0.58–0.86; p < 0.001), and percentage of articular surface involved (intraclass correlation coefficient [ICC], 0.67; 95% CI, 0.54–0.81; p < 0.001); moderate for comminution (kappa, 0.55; 95% CI, 0.39–0.70; p < 0.001) and stability (kappa, 0.54; 95% CI, 0.39–0.69; p < 0.001); and fair for the number of fracture fragments (ICC, 0.39; 95% CI, 0.27–0.57; p < 0.001). When recommending treatment, interobserver agreement was substantial (kappa, 0.69; 95% CI, 0.50–0.88; p < 0.001) for the recommendation to operate or not to operate, but only fair (kappa, 0.34; 95% CI, 0.21–0.47; p < 0.001) for the specific type of treatment, indicating variation in operative techniques. There were no differences in agreement for any of the fracture characteristics or treatment preference between less-experienced and more-experienced surgeons, although statistical power on this comparison was low. None of the surgeon characteristics was associated with the decision for operative treatment, whereas all fracture characteristics were, except for stable and uncertain joint stability. Articular step or gap (β, 0.90; R-squared, 0.89; 95% CI, 0.75–1.05; p < 0.001), likelihood of subluxation or dislocation (β, 0.80; R-squared, 0.76; 95% CI, 0.59–1.02; p < 0.001), and unstable fractures (β, 0.88; R-squared, 0.81; 95% CI, 0.67–1.1; p < 0.001), are most strongly associated with the decision for operative treatment.

Conclusions

We found that assessment of a step or gap and likelihood of subluxation were most reliable and are strongly associated with the decision for operative treatment. Surgeons largely agree on which fractures might benefit from surgery, and the variation seems to be with the operative technique. Efforts at improving the care of these fractures should focus on the comparative effectiveness of the various operative treatment options.

Level of Evidence

Level III, diagnostic study.

Electronic supplementary material

The online version of this article (doi:10.1007/s11999-015-4394-7) contains supplementary material, which is available to authorized users.     

How Are Dysplastic Hips Different? A Three-dimensional CT Study

Background

Surgical correction of acetabular dysplasia can postpone or prevent joint degeneration. The specific abnormalities that make up the dysplastic hip are controversial.

Questions/purposes

(1) What are the relative size, shape, and orientations of the typical nondysplastic hip? (2) How do these variables differ in the developmentally dysplastic hip? (3) Are there version differences between the acetabuli of dysplastic and nondysplastic hips? (4) Are there pairs of variables in which the change in one is always accompanied by a change in the other for both nondysplastic and dysplastic acetabuli?

Methods

Of 117 consecutive three-dimensional (3-D) CT scans performed for hip dysplasia between March 1988 and October 1995, 48 met criteria of developmentally dysplastic hips by plain radiography. These were retrospectively compared with 55 pelvic 3-D CT scans culled from 81 consecutive scans performed for reasons other than hip dysplasia (ie, hip pain, trauma, infection) that did not affect the hip or pelvic landmarks. The 3-D reconstructions were orientated anatomically for standardization of the measurements to be compared. Representative 3-D volumes of the acetabular space were constructed from which we could measure anatomic positions and dimensional information. One author performed all image orientation and measurements.

Results

Nondysplastic acetabuli are essentially hemispheric with height equal to width and twice the depth. The dysplastic acetabuli were elongated in females (52.4 ± 6.2 mm for dysplastic versus 46.5 ± 4.6 mm for nondysplastic (mean difference, 5.0; 95% confidence interval [CI], 1.9–8.0; p = 0.002) and shallower in both females (18.7 ± 4.9 mm for dysplastic versus 23.6 ± 4.0 mm for nondysplastic; mean difference, 6.5; 95% CI, 4.4–8.5; p < 0.0001) and males (21.1 ± 4.8 mm for dysplastic versus 25.0 ± 4.3 mm for nondysplastic, mean difference, 5.3; 95% CI, 2.6–8.1; p = 0.0002); width was similar to that of nondysplastic hips. Acetabular openings were slightly more vertical than nondysplastic hips in females (5°; 95% CI, 1.9–8.1; p = 0.002) but not in male subjects. The dysplastic acetabuli were smaller in volume (18% in females, p = 0.002, and 19% in males, p = 0.0012) and had less space occupied by the femoral head compared with nondysplastic hips (p < 0.0001 for females, p < 0.0001 for males). Dysplastic hip midacetabulum was 4° more anteverted in females (95% CI, 0.5–6.8; p = 0.022) but not for males (p = 0.538). The upper dysplastic acetabulum was more retroverted in females and males (10.2°; 95% CI, 5.5–15; p < 0.0001, and 7.0°; 95% CI, 0.6–13.4; p = 0.032, respectively). Acetabular volumes in nondysplastic and dysplastic hips were related to acetabular width but not to length.

Conclusions

Developmentally dysplastic acetabuli are not deficient in merely a single dimension but are globally deficient. The subluxated femoral head lies in the elongated and retroverted superior acetabulum, which becomes progressively shallower as the acetabulum increases in length. Focally deficient anterior or posterior femoral head coverage is uncommon. Current procedures that redirect the acetabulum, no matter how technically successful, cannot fully compensate for the incongruence of a spherical femoral head within a shallow and elongated acetabulum unless corrected at an early age when acetabular remodeling is possible. Early detection and treatment of acetabular dysplasia should be emphasized.

Level of Evidence

Level III, prognostic study.     

Treatment With the SIGN Nail in Closed Diaphyseal Femur Fractures Results in Acceptable Radiographic Alignment

Background

The burden of orthopaedic trauma in the developing world is substantial and disproportionate. SIGN Fracture Care International is a nonprofit organization that has developed and made available to surgeons in resource-limited settings an intramedullary interlocking nail for use in the treatment of femoral and tibial fractures. Instrumentation also is donated with the nail. A prospectively populated database collects information on all procedures performed using this nail. Given the challenging settings and numerous surgeons with varied experience, it is important to document adequate alignment and union using the device.

Questions/purposes

The primary aim of this research was to assess the adequacy of operative reduction of closed diaphyseal femur fractures using the SIGN interlocking intramedullary nail based on radiographic images available in the SIGN database. The secondary aims were to assess correlations between postoperative alignment and several associated variables, including fracture location in the diaphysis, degree of fracture site comminution, and time to surgery. The tertiary aim was to assess the functionality of the SIGN database for radiographic analyses.

Methods

A review of the prospectively populated SIGN database was performed for patients with a diaphyseal femur fracture treated with the SIGN nail, which at the time of the study totaled 32,362 patients. After study size calculations, a random number generator was used to select 500 femur fractures for analysis. Exclusion criteria included open fractures and those without radiographs during the early postoperative period. The following information was recorded: location of the fracture in the diaphysis; fracture classification (AO/Orthopaedic Trauma Association [OTA] classification); degree of comminution (Winquist and Hansen classification); time from injury to surgery; and patient demographics. Measurements of alignment were obtained from the AP and lateral radiographs with malalignment defined as deformity in either the sagittal or coronal plane greater than 5°. Measurements were made manually by the four study authors using on-screen protractor software and interobserver reliability was assessed.

Results

The frequency of malalignment greater than 5° observed on postoperative radiographs was 51 of 501 (10%; 95% CI, 6.5–11.5), and malalignment greater than 10° occurred in eight of 501 (1.6%) of the femurs treated with this nail. Fracture location in the proximal or distal diaphysis was strongly correlated with risk of malalignment, with an odds ratio (OR) of 3.7 (95% CI, 1.5–9.3) for distal versus middle diaphyseal fractures and an OR of 4.7 (95% CI, 1.9–11.5) for proximal versus middle fractures (p < 0.001). Time from injury to surgery greater than 4 weeks also was strongly correlated with risk of malalignment (p < 0.001). Inherent fracture stability, based on fracture site comminution as per the Winquist and Hansen classification (Class 0–1 stable versus 2–4 unstable) showed an OR of 2.3 (95% CI, 1.2–4.3) for malalignment in unstable fractures. Interobserver reliability showed agreement of 88% (95% CI, 83–93) and mean kappa of 0.81 (95% CI, 0.65–0.87). The SIGN database of radiographic images was found to be an excellent source for research purposes with 92% of reviewed radiographs of acceptable quality.

Conclusions

The frequency of malalignment in closed diaphyseal femoral fractures treated with the SIGN nail closely approximated the incidence reported in the literature for North American trauma centers. Increased time from injury to surgery was correlated with increased frequency of malalignment; as humanitarian distribution of the SIGN nail increases, local barriers to timely care should be assessed and improved as possible. Prospective clinical study with followup, despite its inherent challenges in the developing world, would be of great benefit in the future.

Level of Evidence

Level III, therapeutic study.