Comparing the Pemberton osteotomy and modified San Diego acetabuloplasty in developmental dysplasia of the hip.

PURPOSE: Patients with developmental dysplasia of the hip (DDH) may require a pelvic osteotomy to treat acetabular dysplasia. The Pemberton osteotomy and modified San Diego acetabuloplasty are two options available when surgically treating DDH. The purpose of this study was to compare outcomes following the Pemberton and modified San Diego when treating patients with acetabular dysplasia in typical DDH. METHODS: We included 45 hips in the modified San Diego group and 38 hips in the Pemberton group. Hips with less than two years follow-up and patients with a neuromuscular diagnosis were excluded. Clinical outcomes were rated using the modified McKay criteria with radiographic outcomes graded using the Severin score. Avascular necrosis (AVN) was assessed using the Kalamchi and MacEwen criteria. RESULTS: Mean follow-up was 4.9 years (2.1 to 11.2). Both procedures produced similar decreases in the acetabular index (modified San Diego: 17.0˚ versus Pemberton: 15.2˚; p = 0.846). Most hips had good/excellent results using the modified McKay criteria (modified San Diego: 78%, Pemberton: 94%; p = 0.055). Most hips were rated as good/excellent on the Severin scale (modified San Diego: 100%, Pemberton: 97%, p = 0.485). The proportion of hips with AVN grade 2 or higher were similar between groups (modified San Diego: 0%, Pemberton: 3%; p = 0.458). CONCLUSION: The modified San Diego acetabuloplasty is a safe and effective alternative to treat acetabular dysplasia in patients with typical DDH. By maintaining an intact medial cortex, acetabular reshaping can be customized to address each patient's specific acetabular deficiency. LEVEL OF EVIDENCE: Level III retrospective comparison.

Should paediatricians initiate orthopaedic hip dysplasia referrals for infants with isolated asymmetric skin folds?

PURPOSE: Asymmetric skin folds (ASFs) have been linked to developmental dysplasia of the hip (DDH) in select studies, leading to their inclusion in paediatric practice guidelines regarding orthopaedic referral for hip evaluation. The purpose of this study was to investigate the utility of isolated ASFs as a screening tool for DDH in a series of patient referrals evaluated at a single institution. METHODS: We performed a retrospective review of consecutive patients between 0 and 12 months of age referred to orthopaedic clinics for isolated ASFs. We recorded radiographic findings (acetabular inclination or alpha angle), diagnosis rendered and treatment administered. RESULTS: A total of 66 patients were included (mean age 6.4 months; 2.47 to 10.76). All patients received pelvic radiographs or ultrasound. In all, 36 patients (55%) were considered normal by their treating physician and 25 (38%) were considered dysplastic and underwent brace treatment. One hip with an isolated ASF was found to have a dislocated hip on radiograph prior to their initial orthopaedic visit. None of the patients in this study have required surgery to date. CONCLUSION: Using ASFs as a reason for referral led to increased diagnosis of mild dysplasia resulting in orthotic treatment. Thus, in our particular clinical environment, isolated ASFs can be an indicator of mild dysplasia and warrant further workup or referral. Because treatment philosophies regarding recognition and treatment of mild dysplasia vary amongst centres, the value of screening with ASFs likewise depends on the treating orthopaedic surgeon's threshold for treatment of mild dysplasia. LEVEL OF EVIDENCE: Level IV- Retrospective.

The aetiology of the non-ossifying fibroma of the distal femur and its relationship to the surrounding soft tissues.

PURPOSE: We aim to retrospectively evaluate patients with non-ossifying fibroma (NOF) of the distal femur by radiographs, CT and MRI, and to provide a theory describing the reasoning for the distal femur NOF's location and aetiology. METHODS: Charts of patients with NOFs between 2003 and 2014 were retrospectively reviewed. Inclusion criteria encompassed a diagnosis of NOF of the distal femur by imaging, and histologically, if available. Radiographs, CT and MRI were used to characterise the relationship of the NOF lesions with the surrounding soft tissues. RESULTS: The 68 NOFs from 60 patients were included. By radiograph, 41 (60.3%) of the 68 lesions appeared at the medial and 25 (36.7%) at the lateral aspect of the distal femur. In total, 41 lesions had CT scans, showing 22 NOFs (53.7%) attached to the origin of the medial gastrocnemius, 12 (29.3%) to the origin of the lateral gastrocnemius and four (9.8%) at the attachment of the adductor magnus. Of the CT scans, 93% identified the NOF's relationship with an adjoining tendon of the distal femur. Six had MRIs, all of which showed attachment at the medial gastrocnemius. CONCLUSION: The study reveals a relationship between tendinous structures and NOFs. NOFs of the distal femur occur most commonly at the origin of the medial and lateral gastrocnemius. They may originate from the physis/metaphysis but they do not always attach to the physis, as we observe them 'migrating' as patients grow. More research is required to understand the exact aetiology of NOFs.

Carpenter syndrome: natural history and clinical spectrum.

Recently, we evaluated three sibs with Carpenter syndrome, permitting further clinical, orthopedic, radiographic, and psychometric delineation of this disorder. All three patients were operated on for craniostenosis at or before 2 months. Although all had gross motor delay in early infancy, two had normal intelligence at 12 months and 10 years, respectively. Bony abnormalities contributed to functional impairment especially in the older children. Preaxial polydactyly of feet was present in all three affected sibs and in all other reported individuals with this condition, allowing differentiation of Carpenter syndrome from the other autosomal-recessive acrocephalopolysyndactyly syndromes.

A new "transducer-tipped" fiber optic catheter for measuring intramuscular pressures.

Laboratory and clinical tests were used to determine the efficacy of a new fiber optic "transducer-tipped" catheter for measuring intramuscular pressures. When pressures ranging from 0 to 250 mm Hg were applied by a mercury manometer, the fiber optic system accurately recorded the pressures. In addition, the fiber optic system showed long-term stability by accurately recording the manometer pressure over a 3 day period. The Slit system showed a higher magnitude of hydrostatic pressure artifacts with catheter tip movement as compared to the fiber optic system. The two catheters showed no difference when measuring pressures in pig muscle at rest or when being compressed throughout a range of 0 to 250 mm Hg. In human volunteers, both catheters measured essentially equal pressures at rest, during venous stasis, and during a combination of venous stasis and compression. For long-term assessment, the Slit system required as many as three saline flushes, whereas the fiber optic system measured pressures continuously without manipulation. We conclude that the fiber optic system is as accurate as the Slit catheter for measuring tissue fluid pressures at rest. In addition, the fiber optic system offers distinct advantages over conventional fluid-filled systems for measuring intramuscular pressures due to a lack of hydrostatic pressure artifacts caused by limb position and to the lack of flushing for long-term measurements.

Kappa Delta Award paper. Tissue fluid pressures: from basic research tools to clinical applications.

The two basic research tools developed to measure tissue fluid pressure (wick catheter) and osmotic pressure (colloid osmometer) have undergone extensive validation and refinement over the past 20 years. Using these techniques, basic science investigations were undertaken of edema in Amazon reptiles, pressure-volume relations in animals and plants, adaptive physiology of Antarctic penguins and fishes, edema in spawning salmon, tissue fluid balance in humans under normal conditions and during simulated weightlessness, and orthostatic adaptation in a mammal with high and variable blood pressures--the giraffe. Following and sometimes paralleling this basic research have been several clinical applications related to use of our colloid osmometer and wick technique. Applications of the osmometer have included insights into (a) reduced osmotic pressure of sickle-cell hemoglobin with deoxygenation and (b) reduced swelling pressure of human nucleus pulposus with hydration or certain enzymes. Clinical uses of the wick technique have included (a) improvement of diagnosis and treatment of acute and chronic compartment syndromes, (b) elucidation of tissue pressure thresholds for neuromuscular dysfunction, and (c) development of a better tourniquet design for orthopaedics. This article demonstrates that basic research tools open up areas of basic, applied, and clinical research.

The effect of antivenin on intramuscular pressure elevations induced by rattlesnake venom.

The dose of an antivenin required to neutralize a clinical case of venom poisoning, as well as determining the timing or need to initiate antivenin treatment, is frequently difficult to objectively ascertain. In this study, venom from the southern Pacific rattlesnake, Crotalus viridis helleri, was injected into 29 dog hind limb anterolateral compartments. A solution of C. v. helleri venom (15 mg/ml) was prepared using dessicated venom and saline; 0.2 ml were injected sub-fascially so that each of the compartments received 3 mg of venom. In one group no antivenin was given, in a second group four vials of antivenin were administered i.v. 1 hr post-injection, and in the final group eight vials of antivenin were administered i.v. 1 hr following venom injection. In all groups intracompartment pressures, limb girth and surface temperature were measured at regular intervals over the first 48 hr. In the group receiving eight vials of antivenin the intracompartment pressure reached a peak mean pressure of 49 mm Hg at 2 - 4 hr, and then rapidly fell. In those treated with none or four vials the pressure rose to 70 and 60 mm Hg, respectively, and remained elevated over the first 24 hr. The difference between the former and latter two groups is statistically significant. The findings indicate that the intracompartmental pressure, and presumably destructive damage of the venom, can be controlled by adequate levels of i.v. antivenin. Intracompartmental pressure measurements should be considered as an adjunct in the monitoring and decision-making processes for the treatment of patients bitten by rattlesnakes.

Rattlesnake bites and surgical decompression: results using a laboratory model.

Studies were performed on the hind limbs of dogs and their anterolateral compartments to evaluate the effect of fasciotomy on tissue pressure and necrosis following pit viper envenomation. Venom from the southern Pacific rattlesnake, Crotalus viridis helleri, was injected into either the subcutaneous tissues, the intact anterolateral compartment or the anterolateral compartment following fasciectomy. Interstitial fluid pressure measurements, as well as limb girth and surface temperatures, were obtained over the first 48 hr following venom injection, after which time the compartment contents were examined microscopically. The results demonstrated intracompartment tissue pressure elevations only following intracompartment injections. Fasciectomy prior to injection did not prevent muscle necrosis, though it did reduce maximum compartment pressures. Clinically the limbs in each group could not be differentiated. Intracompartment pressure measurements were able to distinguish between muscle and subcutaneous envenomations by the differences in compartment pressures. These results demonstrate the value of tissue pressure measurements in the evaluation of patients envenomated by rattlesnakes. They also indicate the objectivity necessary to determine the need for surgical decompression.

Double-incision fasciotomy of the leg for decompression in compartment syndromes.

Surgical decompression remains the only effective treatment for the ischemia of the muscles and nerves of the leg that constitutes the principal defects in the compartment syndromes. Recently, partial fibulectomy has been proposed as a good way to decompress all four compartments instead of the older double incision. Both methods are effective in satisfactorily reducing intracompartmental pressures, as documented by our wick catheter measurements. However, the double-incision technique is easier, faster, safer, and is the treatment of choice when four-compartment decompressive fasciotomy is indicated.

Altered fibular growth patterns after tibiofibular synostosis in children.

BACKGROUND: Iatrogenic synostosis of the tibia and fibula following an operation on the leg in a child has been reported rarely in the literature, and the effects of this complication on future growth, alignment, and function are not known. This is a retrospective case series, from one institution, of crossunions of the distal parts of the tibia and fibula complicating operations on the leg in children. The purpose is to alert surgeons to this possible complication. METHODS: The senior author identified eight cases of iatrogenic tibiofibular synostosis seen in children since 1985. The patients had various diagnoses and were from the practices of four pediatric orthopaedic surgeons. Synostosis developed in six patients after osteotomies of the distal parts of the tibia and fibula, in one after internal fixation of distal tibial and fibular metaphyseal fractures through a single incision, and in one after posterior transfer of the anterior tibialis tendon through the interosseous membrane combined with peroneus brevis transfer to the calcaneus. Medical records were reviewed, and preoperative and follow-up radiographs were analyzed for changes in the relative positions of the proximal and distal tibial and fibular physes and in the alignment of the ankle. RESULTS: Five patients were symptomatic after crossunion; they presented with prominence of the proximal part of the fibula, ankle deformity, or ankle pain. Three patients were asymptomatic, and a synostosis was identified on routine follow-up radiographs. Intraoperative technical errors caused two of the crossunions; the cause of the others was unknown. Following tibiofibular synostosis, growth disturbances were noted radiographically in every patient. The normal growth pattern of distal migration of the fibula relative to the tibia was reversed, resulting in a decreased distance between the proximal physes of the tibia and fibula as well as proximal migration of the distal fibular physis relative to the distal part of the tibia. Shortening of the lateral malleolus led to greater valgus alignment of the ankle. CONCLUSIONS: Tibiofibular synostosis can complicate an operation on the leg in a child. After crossunion, the normal distal movement of the fibula relative to the tibia is disrupted, resulting in shortening of the lateral malleolus and ankle valgus as well as prominence of the fibular head at the knee. The synostosis also interferes with the normal motion that occurs between the tibia and fibula with weight-bearing, potentially leading to ankle pain.

One-stage correction of the spastic dislocated hip. Use of pericapsular acetabuloplasty to improve coverage.

We performed a combined one-stage approach for the treatment of eighteen spastic subluxated or dislocated hips in eleven children who had cerebral palsy. All patients were between five and thirteen years old and had spastic subluxation or dislocation of the hip and severe acetabular dysplasia. The operation consisted of release of the adductors, psoas, and proximal hamstrings; a femoral-shortening varusderotation osteotomy; and a pericapsular pelvic osteotomy. The pelvic osteotomy was designed to increase superolateral coverage of the femoral head in the elongated acetabulum, which had erosion of the superior and lateral aspects. At the latest follow-up (mean duration, six years and ten months), seventeen of the eighteen hips remained anatomically reduced.

Complications of posterior arthrodesis of the cervical spine in patients who have Down syndrome.

Ten patients who had Down syndrome and had had a posterior arthrodesis of the upper cervical spine were studied. The mean age at the time of the operation was 8.9 years, and the patients had been followed for three days to forty-nine months. Complications related to the operation occurred in all patients. They included infection and dehiscence at the site of the wound, incomplete reduction of the atlanto-axial joint, instability of the adjacent motion segment, neurological sequelae, resorption of the autogenous bone graft, and death in the postoperative period. Resorption of the bone graft, which occurred in six of the patients, has not previously been reported in patients who have Down syndrome, to our knowledge. Several theoretical mechanisms for this complication are proposed. We recommend non-operative management for patients who have Down syndrome and atlanto-axial instability without neurological signs or symptoms. If the severity of symptoms necessitates a posterior arthrodesis, a high rate of complications must be anticipated.

Acute compartment syndromes: diagnosis and treatment with the aid of the wick catheter.

Intracompartmental pressures were measured by the wick catheter technique in sixty-five compartments of twenty-seven patients who were clinically suspected of having acute compartment syndromes. A pressure of thirty millimeters of mercury or more was used as an indication for decompressive fasciotomy. The range of normal pressure was from zero to eight millimeters of mercury. Eleven of these patients were diagnosed as actually having compartment syndromes and in these patients, twenty-seven compartments were decompressed. Only two patients had significant sequelae. In the sixteen patients (thirty-eight compartments) whose pressures remained less than thirty millimeters of mercury, fasciotomy was withheld and compartment syndrome sequelae did not develop in any patient. Intraoperatively the wick catheter was used continuously in eight patients to document the effectiveness of decompression. Fasciotomy consistently restored pressures to normal except in the buttock and deltoid compartments, where epimysiotomy was required to supplement the fasciotomy. Continuous intraoperative monitoring of pressure by the wick catheter technique allowed us to select the few cases in which primary closure of wounds was appropriate and to decide which patients were best treated with secondary closure.

Quantification of intracompartmental pressure and volume under plaster casts.

UNLABELLED: Infusion lines (to elevate intracompartmental pressure experimentally) and wick catheters (to monitor the pressure produced) were inserted into hind-limb muscle compartments in twenty-six dogs. A padded plaster cast was then applied. The effect of the cast on intracompartmental pressure and volume and the effect of first splitting the cast and then cutting the padding were determined. Three different padding were used: dry Webril, Webril soaked in blood and Betadine (povidone-iodine), and Webril soaked in blood and Betadine and then dried. The cast was found to restrict expansion of the compartment volume by approximately 40 per cent. The most significant reductions in pressure in all groups occurred after the cast was cut and spread (mean reduction, 65 per cent). An additional pressure reduction of 10 to 20 per cent occurred after cutting the Webril. After removal of the cast, all limbs maintained some residual elevation of the intracompartmental pressure. CLINICAL RELEVANCE: This study demonstrates the need in clinical practice for continued evaluation and monitoring of a limb even after the cast has been completely removed because of signs and symptoms of a compartmental syndrome.

The wick catheter technique for measurement of intramuscular pressure. A new research and clinical tool.

The wick catheter technique was developed in 1968 for measurement of subcutaneous pressure and has been modified for easy intramuscular insertion and continuous recording of interstitial fluid pressure in animals and humans. Studies in dogs of the anterolateral compartment of the leg in simulation of the compartment syndrome showed the technique to be accurate and reproducible. The wick catheter technique is capable of important clinical applications in the diagnosis and treatment of acute and chronic compartment syndromes.

Fluid balance within the canine anterolateral compartment and its relationship to compartment syndromes.

Fluid homeostasis within muscle compartments is maintained by four pressures: capillary blood pressure, capillary blood oncotic pressure, tissue-fluid pressure, and tissue fluid oncotic pressure. As determined in the canine anterolateral compartment, capillary blood pressure is 25 +/- 3 millimeters of mercury; capillary blood oncotic pressure, 26 +/- 3 millimeters of mercury, tissue-pbessure, -2 +/- 2 millimeters of mercury; and tissue-fluid oncotic pressure, 11 +/- 1 millimeters of mercury. The wick technique allows direct measurement of tissue-fluid pressure in skeletal muscle and, with minor modifications, is adapted to collect microsamples of interstitial fluid for determinations of tissue-fluid oncotic pressure. The wick technique detects very slight fluctuations in intracompartmental pressure such as light finger compression, injection of small volumes of fluid, and even pulsation due to adjacent arterial pressure. Adjacent muscle compartments may contain different tissue-fluid pressure due to impermeable osseofascial barriers. Our results obtained in canine muscle compartments pressurized by infusion of autologous plasma suggest that risks of muscle damage are significant at intracompartmental pressures greater than thirty millimeters of mercury.

Quantitation of skeletal-muscle necrosis in a model compartment syndrome.

UNLABELLED: Skeletal-muscle necrosis was evaluated in previously pressurized canine compartments using technetium-99m stannous pyrophosphate and classic histological criteria. Intracompartmental necrosis was quantitated in the anterolateral muscle compartment of each dog by uptake of 99mTc stannous pyrophosphate using the contralateral anterolateral compartment as an internal control. Representative specimens of muscle were sampled in experimental and control legs of each dog and were analyzed by qualitative histological techniques. Muscle necrosis was assessed in compartments forty-eight hours after pressurization to levels of ten to 120 millimeters of mercury for eight hours in thirty-seven dogs. In another dog, neither anterolateral compartment was pressurized so that both compartments acted as control muscle. The results in these experiments identify a threshold pressure level (thirty millimeters of mercury) and duration (eight hours) at which significant muscle necrosis occurs at normal blood pressure. Our findings imply that a quantitative relationship exists between incorporation of 99mTc stannous pyrophosphate and the level of intracompartmental pressure. This uptake technique, however, is not suitable for diagnosing compartment syndrome in patients with a threatened compartment syndrome. We suggest that intracompartmental pressure measurements by the wick-catheter technique, in conjunction with clinical findings, offer the best means for diagnosing compartment syndrome. CLINICAL RELEVANCE: Significant muscle necrosis associated with an impending compartment syndrome occurs at a threshold intracompartmental pressure of thirty millimeters of mercury after eight hours. Since time variables are often unknown in suspected compartment syndromes, fasciotomy is recommended when intracompartmental pressure exceeds thirty millimeters of mercury in a patient with normal blood pressure. The use of this threshold pressure level as an indication for fasciotomy requires a device for measuring intracompartmental pressure such as the wick catheter.

Anterior release and fusion in pediatric spinal deformity. A comparison of early outcome and cost of thoracoscopic and open thoracotomy approaches.

STUDY DESIGN: A consecutive series of patients undergoing thoracoscopic anterior spinal release and fusion for scoliosis or kyphosis was compared with a consecutive series of patients treated with an open thoracotomy approach. OBJECTIVES: To compare the early clinical results, costs, and charges of performing an anterior thoracic spinal release and fusion with the two approaches. SUMMARY OF BACKGROUND DATA: The thoracoscopic approach to the spine is gaining acceptance, yet there are little data comparing the technique with standard open methods for the treatment of spinal deformity. METHODS: The first 14 thoracoscopic cases performed at the authors' hospital were compared with 18 open thoracotomy cases treated during the previous 12-month period. In each case the discs were excised and bone grafted before performing a posterior fusion. The early clinical outcomes and the hospital charges/costs were analyzed. RESULTS: The percent curve correction was similar between the thoracoscopic and open methods: scoliosis 56% and 60%, respectively; kyphosis, 88% and 94%, respectively. The blood loss and complication rates were similar between the two groups; however, the chest tube output was greater in the thoracoscopic group. The length of hospital stay was not reduced, and the cost of the open procedure is 29% less than the thoracoscopic approach. The minimally invasive thoracoscopic approach avoids cutting the chest/shoulder musculature, greatly decreasing the morbidity of anterior spinal surgery. CONCLUSIONS: The thoracoscopic technique is a safe and effective alternative to open thoracotomy in the approach to the anterior thoracic spine for the treatment of pediatric and adolescent spinal deformity.

Acute exertional superficial posterior compartment syndrome.

This case report of an acute exertional compartment syndrome involving predominantly the superficial posterior compartment emphasizes several important facts: (1) The subacute recurring syndromes, if left untreated, may develop into an acute syndrome. (2) The diagnostic findings separating the acute syndrome from the chronic forms are marked pain with passive stretch of the involved muscles, paresis, and sensory deficit.8,12,15, (3) In the acute form, immediate fasciotomy is mandatory and often results in full recovery. (4) All four major compartments of the leg are susceptible to chronic or acute compartment syndromes initiated by exertion. These compartments can be decompressed as necessary through a limited skin incision as recently reported.11 (5) The need for an easily obtainable and reproducible method for measuring intracompartment pressures (e.g., the wick catheter technique) is indicated.

The medial tibial stress syndrome. A cause of shin splints.

The medial tibial stress syndrome is a symptom complex seen in athletes who complain of exercise-induced pain along the distal posterior-medial aspect of the tibia. Intramuscular pressures within the posterior compartments of the leg were measured in 12 patients with this disorder. These pressures were not elevated and therefore this syndrome is a not a compartment syndrome. Available information suggests that the medial tibial stress syndrome most likely represents a periostitis at this location of the leg.