Aims. The aims of this study were to characterize the incidence and risk factors associated with stress fractures following periacetabular osteotomy, and to determine their effect on osteotomy union. Methods. We retrospectively reviewed all periacetabular osteotomies (PAOs) performed for developmental dysplasia of the hip (DDH) at one institution over a six-year period between 2012 and 2017. Perioperative factors were recorded, and included demographic and surgical data. Postoperatively, patients were followed for a minimum of one year with anteroposterior and false profile radiographs of the pelvis to monitor for evidence of stress fracture and union of osteotomies. We characterized the incidence and locations of stress fractures, and used univariate and multivariable analysis to identify factors predictive of stress fracture and the association of stress fracture on osteotomy union. Results. A total of 331 patients underwent PAO during the study period with 56 (15.4%) stress fractures: 46 fractures of the retroacetabular posterior column, five cases of ischiopubic stress fracture, and five cases of concurrent ischiopubic and retroacetabular stress fractures. Overall, 86% (48/56) healed without intervention. Univariate analysis revealed that stress fractures occurred more frequently in females (p = 0.040), older patients (mean age 27.6 years (SD 8.4) vs 23.8 (SD 9.0); p = 0.003), and most often with the use of the broad Mast chisel (28.5%; p < 0.001). Multivariable analysis revealed that increasing age (odds ratio (OR) 1.04; 95% CI 1.01 to 1.07; p = 0.028) and use of the broad Mast chisel (OR 5.1 (95% CI 1.3 to 19.0) compared to narrow Ganz chisel; p = 0.038) and surgeon (p = 0.043) were associated with increased risk of stress fracture. Patients with stress fractures were less likely to have healed osteotomies after one-year follow-up (76% vs 96%; p < 0.001). Conclusion. Stress fracture of the posterior column may be an under-recognized complication following PAO, and the rate may be influenced by surgical technique. Consideration should be given to using a narrow chisel during the ischial cut to reduce the risk of stress propagation through the posterior column. Cite this article: Bone Joint J 2022;104-B(9):1017–1024

Stress fractures occurring in the pubis and ischium after peri-acetabular osteotomy (PAO) are not well recognised, with a reported incidence of 2% to 3%. The purpose of this study was to analyse the incidence of stress fracture after Bernese PAO under the care of two high-volume surgeons. The study included 359 patients (48 men, 311 women) operated on at a mean age of 31.1 years (15 to 56), with a mean follow-up of 26 months (6 to 64). Complete follow-up radiographs were available for 348 patients, 64 of whom (18.4%) developed a stress fracture of the inferior pubic ramus, which was noted at a mean of 9.1 weeks (5 to 55) after surgery. Most (58; 91%) healed. In 40 of the patients with a stress fracture (62.5%), pubic nonunion also occurred. Those with a stress fracture were significantly older (mean 33.9 years (16 to 50) vs 30.5 years (15 to 56), p = 0.002) and had significantly more mean pre-operative deformity: mean centre–edge angle (9.8° (-9.5 to 35) vs 12.4° (-33 to 28), p = 0.04) and mean Tönnis angle (22.8° (0 to 45) vs 18.7° (-2 to 38), p < 0.001). The pubic nonunion rate was significantly higher in those with a stress fracture (62.5% vs 7%, p < 0.001), with regression analysis revealing that these patients had 11.8 times higher risk than those without nonunion. Cite this article: Bone Joint J 2015; 97-B:24–8

Five elderly patients with chronic pyrophosphate arthropathy developed stress fractures of the tibia. All patients had deformed, painful knees with the result that their increasing symptoms were not readily attributed to a stress fracture. Such a possibility should be considered in patients with chronic pyrophosphate arthropathy since early recognition makes management of the stress fracture easier

We have shown that stress fractures can be induced in the tibial diaphysis of an animal model by the repeated application of non-traumatic impulsive loads. The right hind limbs of 31 rabbits were loaded for three to nine weeks and changes in the bone were monitored by radiography and bone scintigraphy. The presence of stress fractures was confirmed histologically in some cases. Most animals sustained a stress fracture within six weeks and there was a positive correspondence between scintigraphic change and radiological evidence. Microscopic damage was evident at the sites of positive bone scans. The progression, location, and time of onset of stress fractures in this animal model were similar to those in clinical reports, making the model a useful one for the study of the aetiology of stress fractures

A high stress fracture of the fibula which occurred in 48 out of a class of 120 recruits doing a difficult jumping exercise is described. No more were seen when the exercise was stopped. The importance of this report is that it confirms the theory that different muscular activities cause different stress fractures

Seven patients with stress fractures of the femoral neck were treated at the Military Hospital of Thessaloniki, Greece between 1972 and 1976. Their average age was 22 years. Stress fractures of the femoral neck are not as common as stress fractures of the metatarsals or tibia and other bones. Intense muscular activity was the main cause of these stress fractures which were only classed as such in the absence of any injury. Pain and stiffness around the hip were reported by all seven patients before admission. Results of laboratory investigations of the patients' alkaline phosphatase and serum calcium levels were normal. One patient received surgical treatment and the other patients were treated conservatively. Healing was uneventful in all

In two years we treated four women with ununited stress fractures of their proximal tibial diaphyses. They all had arthritis and valgus deformity. The stress fractures had been treated elsewhere by non-operative means in three patients and by open reduction and internal fixation in one, but had failed to unite. After treatment with a modular total knee prosthesis with a long tibial stem extension, all the fractures united. A modular total knee prosthesis is suitable for the rare and difficult problem of ununited tibial stress fractures in patients with deformed arthritic knees since it corrects the deformity and the adverse biomechanics at the fracture site, stabilises the fracture and treats the arthritis

Objectives. The exact aetiology and pathogenesis of microdamage-induced long bone fractures remain unknown. These fractures are likely to be the result of inadequate bone remodelling in response to damage. This study aims to identify an association of osteocyte apoptosis, the presence of osteocytic osteolysis, and any alterations in sclerostin expression with a fracture of the third metacarpal (Mc-III) bone of Thoroughbred racehorses. Methods. A total of 30 Mc-III bones were obtained; ten bones were fractured during racing, ten were from the contralateral limb, and ten were from control horses. Each Mc-III bone was divided into a fracture site, condyle, condylar groove, and sagittal ridge. Microcracks and diffuse microdamage were quantified. Apoptotic osteocytes were measured using TUNEL staining. Cathepsin K, matrix metalloproteinase-13 (MMP-13), HtrA1, and sclerostin expression were analyzed. Results. In the fracture group, microdamage was elevated 38.9% (. sd 2.6. ) compared with controls. There was no difference in the osteocyte number and the percentage of apoptotic cells between contralateral limb and unraced control; however, there were significantly fewer apoptotic cells in fractured samples (p < 0.02). Immunohistochemistry showed that in deep zones of the fractured samples, sclerostin expression was significantly higher (p < 0.03) than the total number of osteocytes. No increase in cathepsin K, MMP-13, or HtrA1 was present. Conclusion. There is increased microdamage in Mc-III bones that have fractured during racing. In this study, this is not associated with osteocyte apoptosis or osteocytic osteolysis. The finding of increased sclerostin in the region of the fracture suggests that this protein may be playing a key role in the regulation of bone microdamage during stress adaptation. Cite this article: N. Hopper, E. Singer, F. Henson. Increased sclerostin associated with stress fracture of the third metacarpal bone in the Thoroughbred racehorse. Bone Joint Res 2018;7:94–102. DOI: 10.1302/2046-3758.71.BJR-2016-0202.R4

Of 66 recruits who sustained stress fractures during basic training and returned to training after a period of rest, seven (10.6%) suffered recurrent fractures within one year. None of the recurrences was at the original anatomical site. All of the recruits with recurrent stress fractures had had at least one of their initial stress fractures in the femur. This suggests that a femoral stress fracture carries a high risk of recurrence at other sites

Thirteen patients suffering from rheumatoid arthritis had 19 stress fractures of the tibia or fibula. These patients characteristically presented with sudden, severe, unexplained pain with localised tenderness just below the knee or above the ankle. In seven patients examination of the adjacent joint indicated a flare-up of disease activity or a pyogenic arthritis. In six patients the diagnosis was delayed by the late appearance of callus in minute fractures. All patients had rheumatoid deformities of the ipsilateral lower limb: valgus deformities of the knee and subtalar joints occurred most frequently. All patients had osteoporosis; all except two had received steroid treatment and five had abnormalities of calcium metabolism. We suggest that deformities of the knee and ankle predispose patients with rheumatoid arthritis and osteoporosis to stress fractures of the tibia and fibula

In a prospective study of 295 male Israeli military recruits a 31% incidence of stress fractures was found. Eighty per cent of the fractures were in the tibial or femoral shaft, while only 8% occurred in the tarsus and metatarsus. Sixty-nine per cent of the femoral stress fractures were asymptomatic, but only 8% of those in the tibia. Even asymptomatic stress fractures do, however, need to be treated. Possible explanations for the unusually high incidence of stress fractures in this study are discussed

During a four-month period we observed 12 stress fractures of the inferior pubic ramus in 11 military recruits undergoing basic training. Eleven of these were in women. This high number was considered to be caused by the introduction of mixed training of male and female recruits; this forces women to increase their stride length when marching. The presenting symptom was chronic groin pain which failed to settle with rest, and the clinical diagnoses were confirmed by radiographs in all but one patient who was diagnosed by . 99m. Tc bone scanning. Since the required stride length has been reduced there have been no new cases of stress fracture of the pelvis

We report a prospective study of 783 male Israeli recruits aged from 17 to 26 years. The risk of stress fracture was inversely proportional to age on both univariate and multivariate analysis. Each year of increase of age above 17 years reduced the risk of stress fracture by 28%

Three women with osteoarthritis of the knee presented after sudden worsening of their symptoms. In each case this was found to be due to a stress fracture of the tibia. With treatment by rest and reduced activity, the fracture healed uneventfully in all three patients

A prospective study of 295 infantry recruits has shown that the mediolateral width of the tibia measured radiographically at each of three different levels in the bone had a statistically significant correlation with the total incidence of stress fractures as well as with those in the tibia alone or the femur alone. A narrow tibial width was shown to be a risk factor, but cortical thickness was not found to be significant

Four military recruits with complete distraction-type stress fractures of the femoral neck were treated conservatively. The radiographic diagnosis was made within two weeks of the onset of symptoms and the activities of the patients were matched to the clinical and radiographic progress of fracture healing. None of the fractures displaced and union occurred uneventfully. Our experience suggests that prophylactic internal fixation of these fractures is not necessary

Stress fractures of the tarsal navicular do not heal predictably with conservative treatment, so we recommend operation if the fracture remains symptomatic, and radiographs show wide separation of a complete fracture, extension of an incomplete fracture, delayed healing, or a medullary cyst. An autologous bone graft is inserted after en-bloc resection of the fracture surfaces. It is important that the fracture is fully exposed to its distal limits before the graft is inserted. We have grafted 19 fractures in 18 patients. Six fractures were complete, 12 incomplete and one had a residual medullary cyst. Of the 15 patients with adequate follow-up, 12 had been able to return to a pre-injury level of activity by five to 12 months

1. The aetiology of a destructive lesion through a former interspace in a spine fused by ankylosing spondylitis is reviewed. 2. From the findings in three patients treated by anterior spinal fusion, evidence was obtained to show that a stress fracture, originating posteriorly between two fused spinous processes, leads to a pseudarthrosis between two vertebral bodies that may simulate a tuberculous lesion. 3. If spinal fusion is indicated, the anterior approach is recommended, both for direct observation of the lesion and to achieve sound union