Purpose:
The anterior centre-edge angle (ACEA) describes anterior acetabular coverage on false profile radiographs. Variability associated with pelvic tilt, radiographic projection, and identifying ...the true anterior edge, causes discrepancies in measuring an accurate ACEA. Computed tomography (CT) has the potential of improving the accuracy of ACEA. However, because the ACEA on sagittal CT has been shown to not be equivalent to ACEA on false profile radiographs, the normal range of ACEA on CT currently remains unknown and cannot reliably be used to determine over/under coverage. We therefore asked: what is the normal variation of ACEA corrected for pelvic tilt on sagittal CT and how does this compare to dysplastic hips?
Material and Methods:
A retrospective review was conducted on patients 10–35 who underwent CT for non-orthopedic related issues and patients with known hip dysplasia. The ACEA was measured on a sagittal slice corresponding to the centre of the femoral head on the axial slice and adjusted for pelvic tilt. A statistical comparison was then performed.
Results:
A total of 320 normal patients and 22 patients with hip dysplasia were reviewed. The mean ACEA for all ages was 50° ± 8°, (range: 23–81º), with a larger mean ACEA for males (51°) than females (49°). The ACEA mean for dysplastic hips was 30° ± 11° with a statistically significant difference in mean from the normal hip group (p < 0.0001).
Conclusion:
The ACEA can be reliably measured on sagittal CT and significantly differs from dysplastic hips. ACEA measurements above 66° or below 34° may represent anterior over and under coverage.
Avascular necrosis of the femoral head (AVNFH) is a debilitating disease that requires early intervention to prevent subchondral collapse and irreversible damage leading to premature hip replacement. ...Patients presenting with AVNFH can have concomitant intra-articular pathology, including femoroacetabular impingement (FAI), that contributes to their hip pain and dysfunction. It is important to restore the native hip anatomy in addition to providing revascularization of necrotic areas to reduce pain, improve function, and maximize efforts to preserve the joint. The purpose of this Technical Note is to describe our preferred arthroscopic approach to core decompression through the femoral neck in combination with femoral osteoplasty to address AVNFH and FAI in a single-staged and minimally invasive procedure.
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Background:
Achieving adequate acetabular correction in multiple planes is essential to the success of Periacetabular Osteotomy (PAO). Three-dimensional (3D) modeling and printing has the potential ...to improve preoperative planning by accurately guiding intraoperative correction.
Hypothesis/Purpose:
We, therefore, asked the following questions: 1) For a patient undergoing a PAO, does 3D-modeling with intraoperative 3D-printed models create a reproducible surgical plan to obtain predetermined parameters of correction including lateral center-edge angle (LCEA), anterior center-edge angle (ACEA), Tonnis angle, and femoral head extrusion index (FHEI), 2) Can 3D computer modeling accurately predict when a normalized FHEI can be achieved without the need for a concomitant femoral sided osteotomy?
Methods:
A retrospective review was conducted on forty-two (42) consecutive patients that underwent a PAO. 3D-modeling software was utilized to simulate a PAO in order to achieve normal LCEA, ACEA, Tonnis angle, and FHEI. If adequate FHEI was not achieved, a femoral osteotomy was simulated. 3D-models were printed as intraoperative guides. Preoperative, simulated, and postoperative ACEA, LCEA, Tonnis angle, and FHEI were measured and compared statistically.
Results:
40 patients had a traditional PAO, and 2 had an anteverting-PAO. The simulated LCEA, ACEA, Tonnis angle, and FHEI were within a median difference of 3º, 1º, 1°, and 0% of postoperative values, respectively and showed no statistical difference. Of those that had a traditional PAO, all thirty-four (34) patients were correctly predicted to need a traditional acetabular sided correction alone and the other six (6) were correctly predicted to need a concomitant femoral osteotomy for a correct prediction in 100% of patients.
Conclusion:
This study demonstrated that in PAO, 3D-modeling and printing allow the surgeon to accurately create a reproducible surgical plan to obtain predetermined postoperative hip coverage parameters. This new technology has the potential to improve preoperative/intra-operative decision making for hip dysplasia and other complex disorders of the hip.
Background
Although the second (S2) and third (S3) sacral segments have been established as potential osseous fixation pathways for screw fixation, the S2 body has been demonstrated to have inferior ...bone density when compared to the body of the first (S1) sacral segment. Caution regarding the use of iliosacral screws at this level has been advised as a result. As transiliac–transsacral screws traverse the lateral cortices of the posterior pelvis, they may be relying on bone with superior density for purchase, which could obviate this concern. The objective of this study was to compare the bone density of the posterior ilium and sacroiliac joint to that of the sacral body at the first (S1), second (S2), and third (S3) sacral levels.
Materials and methods
A retrospective case series was performed, reviewing the CT scans of 100 patients without prior pelvic trauma. Each CT was confirmed to have available osseous fixation pathways at the first (S1), second (S2), and third (S3) sacral segments. The bone density of the posterior ilium/sacroiliac joint (PISJ) and sacral body (SB) was measured using the embedded standardized Hounsfield units (HU) tool at each sacral level.
Results
The average S2 PISJ bone density (320.1) was significantly higher than the S1 (286.5) and S3 (278.9) PISJ (
p
< 0.0001) and S1 and S3 PISJ was not statistically different. The S1 sacral body bone density (231.1) was significantly higher than the S2 (182.1) and S3 (126.8) bone density (
p
< 0.0001). The PISJ bone density is greater than the sacral body at every sacral level (
p
< 0.0001).
Conclusion
The S2 PISJ bone density is significantly greater than S1. The S1, S2, and S3 PISJ bone density is greater than the sacral body at all sacral levels, and the S1 body has higher bone density than the S2 and S3 bodies. These differences in bone density may have implications for the stability of posterior pelvic ring fixation constructs with regard to screw purchase.
Level of evidence
Level III—Case cohort series.
Objectives:
The objectives of this study were to determine the prevalence, pattern, and predisposing factors for sciatic, femoral, obturator, and pudendal nerve injury during hip arthroscopy in the ...pediatric population.
Methods:
We retrospectively reviewed charts of all pediatric patients who underwent hip arthroscopy with neuromonitoring from 2013 until May 2018. Neuromonitoring included when traction was applied and removed, and somatosensory evoked potentials (SSEP) in the peroneal and posterior tibial nerves and electromyography (EMG) signal for the obturator, femoral, and peroneal and posterior tibial branch of the sciatic nerves. Each report was reviewed for total traction time, EMG changes, SSEP changes more than 50% after traction application, and the time for SSEPs to return to baseline. Demographic data and postoperative notes were reviewed for any signs of clinical nerve injury and if/when recovery occurred. We determined the rate of SSEP and EMG changes, time from traction onset to SSEP and EMG changes, time after traction released until SSEP returns to baseline, and rate of neuropraxia and any potential risk factors.
Results:
We identified 78 patients who underwent hip arthroscopy (16±2 years of age; 54 females). Reasons for hip arthroscopy included femoral acetabular impingement (37%), hip dysplasia with labral tear (27%), slipped capital femoral epiphysis (23%), labral tear (5%), snapping hip (3%), diagnostic scope (3%), Perthes with labral tear (1%), and trauma (1%). Average traction time was 64±30 min. SSEPs decreases of less than 50% occurred in 76% of patients in the peroneal nerve, and 69% of patients in the posterior tibial nerve. In the contralateral limb, there was a 50% drop in SSEPs in the peroneal nerve in 13% of patients and in the posterior tibial nerve in 8% of patients. For the peroneal nerve, this drop in signal occurred 23±11 min after traction was applied and returned intraoperatively at a rate of 74% 29±23 min after traction removal. For the posterior tibial nerve, this drop in signal occurred 22±12 min after traction was applied and returned intraoperatively at a rate of 83% 24±15 min. after traction removal. EMG activity was observed after traction application in 10% of patients in the obturator nerve at 36±34 min., 9% of patients in the femoral nerve at 22 ± 15 min., 14% of patients in the peroneal nerve at 19±27 min, and 5% of patients in the posterior tibial nerve at 42±42 min. The rate of pudendal nerve neuropraxia was 0%. The rate of clinical neuropraxia postoperatively was 18%. Those who sustained a neuropraxia had on average a 54 min. longer surgery (p=0.005) and a trend towards a 14 min. longer traction time (p=0.096). Diagnosis had no statistical effect on the rate of clinical diagnosis.
Conclusion:
Hip arthroscopy is increasingly utilized to treat several unique diagnoses in the pediatric population. As such, it is important to understand the potential risks of treating different diagnosis in this population. The important findings of this study are that neuromonitoring changes occur in more than 70% of patients and 18% will have some decreased sensation in either their peroneal nerve or posterior tibial nerve that resolves within 1-2 days after surgery. There is also a low risk of neuropraxia if there are no neuromonitoring changes during surgery. Diagnosis (Hip dysplasia/SCFE/FAI) did not change incidence of neuropraxia. Longer surgery and traction time appear to be the only risk factors for neuropraxia in hip arthroscopy in pediatric patients.
Background:
Pediatric forearm fractures are a common injury with only a small subset of these involving the distal physes of the radius and ulna. A common mechanism of injury in these fractures are ...from sports related injuries or fall on outstretch hand. Physeal fractures of the distal radius are well-studied, with varying rates of growth arrest and potential for deformity depending on the type of physeal fracture. The incidence and long-term complications of pediatric forearm fractures involving the distal ulna physis remains largely unknown. Distal ulnar physeal arrest can lead to the development of radioulnar length discrepancy and angular deformities. Two previous studies of limited sample size report a 50-55% of physeal arrest when the ulnar physiss was involved in the fractur, which seems higher than what is seen at our institution. The purpose of this study was to investigate the demographic distribution, as well as the incidence of physeal arrest following a physeal fracture of the distal ulna.
Methods:
After institutional review board approval, a retrospective study was performed of all patients with distal forearm fractures treated at our institution from January 2003 until December 2017. We included patients < 18 years of age who presented to our level-1 emergency department or to our orthopaedic department and excluded those with extra-physeal fracture and closed physis. Wrist x-rays of 1,618 patients with distal forearm fractures were reviewed revealing a total of 52 patients with distal ulna physeal fracture. Patient demographics including age, gender, height, weight, mechanism of injury, and age at follow up was recorded. Each injury x-ray was reviewed and the distal ulna physeal fracture was categorized using the Salter-Harris (SH) classification system. Concomitant injuries were also recorded and if there was a radial physeal injury the SH classification system was used again. All follow up radiographs > 6 months post-injury were reviewed to assess for physeal arrest.
Results:
There were a total of 11 patients (average age at injury 10 ± 2 years; 5 males, 6 females; average height 1.5 0.2 m, average weight 47 ± 23 kg) with at least 6 months follow up post injury (average follow up time 2.4 ± 2.2 years. Of these, the most common mechanism was fall on outstretch hand occurring 64% of the time (n = 7), followed by sports in 18% (1 football, 1 baseball), and 9% fall from bike (n = 1), and 9% from ATV accident (n = 1). The most frequent distal ulna physeal fracture was SH type 2 occurring 55% of the time (n = 6), while 36% had a SH type 3 (n = 4), and 9% had a SH type 1 (n = 1). Eight patients had an ipsilateral radius fracture with 45% having a metaphyseal fracture (n = 5) and 27% having a distal radius physeal fracture (n = 3; one SH type 1, and two SH type 2). One patient had an ipsilateral supracondylar fracture and another patient had a Galeazzi fracture. Casting was the most frequent treatment occurring 64% of the time (n = 7), followed by closed reduction and casting in 18% (n = 2). Closed reduction and percutaneous pinning was done in 9% (n = 1), and open reduction and internal fixation (ORIF) was done in 9% (n = 1). None of these patients developed distal ulna physeal arrest (while one of them developed a distal radius physeal arrest. The one patient with the Galezzi fracture did go on to develop a malunion with clicking of his wrist despite being treated with ORIF and required a revision osteotomy 7 months later. The remainder of patients had no complications.
Conclusion/Significance:
The most important finding of this study is that the rate of distal ulna physeal arrest following fracture was 0%. This is in contrast to previous studies of limited sample size that reported a rate of 50-55%. Our results demonstrate a much lower incidence of distal ulnar physeal arrest than previously thought in the pediatric population with distal forearm fractures. These findings suggest that the majority of patients with distal ulna physeal fractures do well with conservative management, and may only require routine clinical and radiographic follow up.
We report a novel case of a patient who had a draining sinus soon after a total hip arthroplasty that spontaneously resolved. The patient voluntarily discontinued antibiotic suppressive therapy (AST) ...after 10 years of treatment and paradoxically experienced full resolution of signs of chronic prosthetic joint infection (PJI), including recovery of his left-sided draining sinus tract. Now 8 years after discontinuing AST, the patient has no pain, good function, and no major or minor criteria of joint infection according to the Musculoskeletal Infection Society (MSIS) workgroup. The authors have not identified literature describing a similar resolution of draining sinus tracts from around a prosthetic joint after discontinuing AST. Despite the resolution of this patient’s sinus tract, the authors do not advocate for discontinuing AST in patients with a draining sinus tract. However, in spite of the fact that the MSIS consensus statement suggests that a draining sinus is a sure sign of PJI and that the assumption is that the infection will not go away until explant, this case was different.
We report a novel case of a pediatric patient with bilateral hip destruction from untreated Juvenile idiopathic arthritis (JIA). She was presented at the age of 9 with hip pain associated with ...bilateral acetabular dysplasia and a dislocated left femoral head. Only 1.5 years later, the patient developed complete destruction of the left femoral head and dislocated right femoral head. The authors have not identified literature describing a similar case report of bilateral femoral head destruction resulting from Persistent Oligoarticular JIA. Pediatric patients presenting with rapidly evolving destructive process should be evaluated for rheumatologic, infectious, and spinal etiologies.
Background:
Hip arthroscopy continues to evolve for treating hip pathologies disorders. With this evolution, comes an awareness of its associated complications. One potential side effect is damage to ...the nerves about the hip, usually affecting the pudendal or sciatic nerve. In one study of 60 adults, 58% of the patients had intraoperative nerve dysfunction and 7% sustained a clinical nerve injury. It has been reported that the rate of pediatric pudendal nerve palsy ranges from < 1% to 6% following hip arthroscopy. However, the rate of sciatic nerve injury during hip arthroscopy in the pediatric population is unknown. As such, the objectives of this study were to determine the 1) prevalence, pattern, and predisposing factors for sciatic, femoral, and obturator nerve injury during hip arthroscopy in the pediatric population, and 2) were there any risk factors associated with nerve injury during hip arthroscopy in the pediatric population?
Methods:
We retrospectively reviewed charts of all pediatric patients who underwent hip arthroscopy with neuromonitoring from 2013 until May 2018. Neuromonitoring included when traction was applied and removed, and somatosensory evoked potentials (SSEP) in the peroneal and posterior tibial nerves and electromyography (EMG) signal for the obturator, femoral, and peroneal and posterior tibial branch of the sciatic nerves. Each report was reviewed for total traction time, EMG changes, SSEP changes more than 50% after traction application, and the time for SSEPs to return to baseline. Demographic data and postoperative notes were reviewed for any signs of clinical nerve injury and if/when recovery occurred. We determined the rate of SSEP and EMG changes, time from traction onset to SSEP and EMG changes, time after traction released until SSEP returns to baseline, rate of neuropraxia and any potential risk factors, and the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of SSEP changes in predicting neuropraxia. Risk factors for neuropraxia were assessed using a Wilcoxon Rank Sums test between those who sustained a neuropraxia and those who did not.
Results:
We identified 78 patients who underwent hip arthroscopy (16±2 years of age; 24 males, 54 females; BMI 26 ± 6 kg/m2). Reasons for hip arthroscopy included femoral acetabular impingement (37%, N=29), hip dysplasia with labral tear (27%, N=21), slipped capital femoral epiphysis (23%, N=18), labral tear (5%, N=4), snapping hip (3%, N=2), diagnostic scope (3%, N=2), Perthes with labral tear (1%, N=1), and trauma (1%, N=1). Average traction time was 64±30 min. SSEPs decreases of less than 50% occurred in 76% of patients (N=59) in the peroneal branch of the sciatic nerve, and 69% of patients (N=54) in the posterior tibial branch of the sciatic nerve. In the contralateral limb, there was a 50% drop in SSEPs in the peroneal branch of the sciatic nerve in 13% of patients (N=10) and in the posterior tibial branch of the sciatic nerve in 8% of patients (N=6). For the peroneal nerve, this drop in signal occurred 23±11 min after traction was applied and returned intraoperatively at a rate of 74% 29±23 min after traction removal. For the posterior tibial nerve, this drop in signal occurred 22±12 min after traction was applied and returned intraoperatively at a rate of 83% 24±15 min. after traction removal. EMG activity was observed after traction application in 10% of patients in the obturator nerve at 36 ± 34 min., 9% of patients in the femoral nerve at 22 ± 15 min., 14% of patients in the peroneal nerve at 19±27 min, and 5% of patients in the posterior tibial nerve at 42±42 min. The rate of clinical neuropraxia postoperatively was 18% (N=14), manifesting as sensory disruption in the peroneal nerve in 11 patients, sensory and motor disruption of the peroneal nerve in 2 patients, sensory disruption in the posterior tibial nerve in 1 patient, and 1 patient with combined sensory peroneal and posterior tibial nerve disruption. Thus, the drop in SSEPs in predicting a postoperative clinical neuropraxia of the peroneal nerve yields a sensitivity of 64%, a specificity of 28%, a PPV of 20%, and a NPV value of 95%. For the posterior tibial nerve, the sensitivity is 100%, specificity is 21%, PPV is 4%, and NPV is 100%. In all cases, the neuropraxia resolved before the first postoperative visit. Those who sustained a neuropraxia had on average a 54 min. longer surgery (p = 0.0053) and a trend towards a 14 min. longer traction time (p = 0.0955).
Conclusion:
Hip arthroscopy continues to have more uses in the pediatric population. As such, it is important to understand the potential risks with this surgery. The important findings of this study are that neuromonitoring changes occur in more than 70% of patients and nearly 20% of patients will have some decreased sensation in either their peroneal nerve or posterior tibial nerve that resolves within 1-2 days after surgery. Another important finding is that there is a low risk of neuropraxia if there are no neuromonitoring changes during surgery. Finally, longer surgery and traction time appear to be the only risk factors for neuropraxia in hip arthroscopy in pediatric patients.
To compare the efficacy of plain x-ray images and computed tomography (CT) to assess the morphology of the lateral wall (LW) component of intertrochanteric (IT) femur fractures and determine ...predictors of early fixation failure.
Retrospective cohort study.
Level-one trauma center.
One hundred forty-two adult patients with IT fractures treated with either a sliding hip screw (SHS) or a cephalomedullary nail (CMN) who had both pre-op plain x-ray images and CT scans with at least 6 weeks of follow-up were reviewed.
Preoperative CT scan and plain radiographs of the affected hip.
Lateral wall assessment based on plain x-rays versus CT imaging in relation to implant failure.
One hundred forty-two patients met inclusion criteria, 105 patients treated with a CMN, and 37 with a SHS. There was a poor correlation between the assessment of the LW on plain x-ray images and CT scans. Failures in the SHS group were significantly associated with all CT measurements (
< .05) but not with plain film LW assessment (
= .66). Fifteen patients had an early implant failure (6 CMN, 9 SHS). There were no statistically significant associations between any radiographic measurement (plain images and CT) and CMN failures.
Plain film images are not accurate for assessing lateral wall morphology/integrity and are not predictive of SHS implant failures. Our novel CT measurements were effective at detecting lateral wall patterns at risk for treatment failure with SHS implants.Level of Evidence: Level III.
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