Treatment of relapsed, residual and neglected clubfoot: adjunctive surgery.

Over the past two decades, the Ponseti 'conservative' (non-surgical) method of clubfoot treatment has been almost universally adopted worldwide. As a result, the need for operative treatment for clubfoot has decreased dramatically. However, even Ponseti himself routinely used surgery for certain patients: at least 90% of feet need percutaneous tenotomy, and 15% to 40% may require tibialis anterior tendon transfer. Additionally, relapses are common, sometimes necessitating further surgical intervention. Relapses are recurrent deformities in previously well corrected feet. Residual deformities may be defined as persistent deformities in incompletely corrected feet. In addition, in many parts of the developing world, neglected clubfoot is still a major challenge. Many neglected feet can be treated with Ponseti principles, particularly in younger children. However, in older children and adults, surgical approaches are more likely to be needed. Major reasons for relapsed/residual clubfoot include incomplete application of the Ponseti principles, inability to adhere to the foot abduction brace protocol, failure to recommend a complete course of bracing and inadequate follow-up. Sometimes, despite excellent treatment, and perfect adherence to the bracing protocols, there are still relapses, related to intrinsic muscle imbalance. We describe several solutions that include reinstitution of Ponseti casting and 'á la carte' operative treatment. As an alternative for particularly stubborn cases, application of a hexapod external fixator can be a powerful tool. In order to be a full-service clubfoot specialist, and not only a Ponseti practitioner, one must have in their toolbox the full gamut of adjunctive surgical options. LEVEL OF EVIDENCE: V.

Growth modulation in idiopathic angular knee deformities: is it predictable?

PURPOSE: To evaluate the temporal and spatial sequence of events following temporal hemiepiphysiodesis in idiopathic knee varus/valgus. METHODS: This is a retrospective multicentre study on 372 physes in 206 patients. The average rate of correction (ROC) was calculated; univariate and multivariate analysis were performed. RESULTS: In all, 92% of the femoral physes were followed for more than one year/reached skeletal maturity. Of those, 93% were corrected to a mechanical lateral distal femoral angle (mLDFA) of 85° to 89°; 2% did not, while 5% were over-corrected. A total of 92% of the tibial physes were followed for more than one year/reached skeletal maturity. Of those, 92% were corrected to a mechanical medial proximal tibial angle (mMPTA) of 85° to 89°; 2% did not, while 6% were over-corrected. Factors significantly influencing success and ROC were age, direction and magnitude of deformity. Femoral ROC was significantly faster than tibial ROC: 0.85° versus 0.78°/month, respectively (p = 0.05). Femoral valgus ROC was significantly faster than varus ROC: 0.90° versus 0.77°/month, respectively (p = 0.04). A constant was derived to calculate the amount of correction. Significant correlation was found between calculated and actual mLDFA in valgus deformity during the first year (r = 0.58 to 0.87, p < 0.01). Calculated mLDFA of varus deformity did not correlate with actual mLDFA. Significant correlation was found when calculating mMPTA correction in all deformities. CONCLUSIONS: Femur corrects faster than tibia; valgus femoral deformities are corrected faster than varus. Valgus correction in the distal femur/proximal tibia as well as varus correction in the tibia in idiopathic patients is highly predictable. The constant derived is the first tool which enables predicting and monitoring amount of correction in hemiepiphysiodesis when correcting angular deformities around the knee. LEVEL OF EVIDENCE: IV.

Hemiepiphysiodesis using tension band plates: does the initial screw angle influence the rate of correction?

PURPOSE: When using tension band plates for angular deformity correction, the literature is unclear regarding the most effective screw insertion angle to use. This study evaluates the correlation between initial screw angle and the average rate of correction during hemiepiphysiodesis using tension band plates. METHODS: This retrospective study includes 35 patients (47 physes) with genu valgum deformity (17 idiopathic and 18 fibular hemimelia) who underwent insertion of Eight-Plates between 2010 and 2015. Initial screw angle was determined from the intraoperative fluoroscopic images. Radiographs were obtained within three months of surgery, and follow-up films were obtained every three to six months. Change in mechanical lateral distal femoral angle, medial proximal tibial angle and screw angle was obtained from each follow-up radiograph. Initial screw angle was correlated with the average rate of correction during the entire treatment period. The average rate of angular correction during first and last follow-up periods was also compared. RESULTS: The relationship between the initial screw angle and the mean rate of angular correction was not statistically significant (p = 0.2). The rate of angular correction during the first follow-up period (mean of 4.7 months) was 0.86° per month compared with 0.71° per month during the last follow-up period (mean of 5.1 months). CONCLUSION: Application of a tension band plate with a divergence angle ranging from 0° to 30° results in similar rates of angular correction. For surgeons inserting screw-plate tension band devices, there does not seem to be any necessity to make the screws parallel or divergent. We recommend that screw placement be anatomically correct, i.e. not impinging on the physis, rather than favouring any particular divergence angle. LEVEL OF EVIDENCE: IV.

Guided growth: preliminary results of a multinational study of 967 physes in 537 patients.

BACKGROUND: Guided growth by tension band plating is commonly used to correct coronal plane deformity. The purpose of this study was to measure the effect and further define parameters that influence results in coronal plane deformity around the knee. METHODS: The retrospective multicentre study included data on 967 physes in 537 patients, with an average follow-up of 16 months after plate insertion. Alignment analysis was compared preoperatively and in at least two measurements postoperatively, as well as with parameters that influence the rate and amount of correction. RESULTS: Average age at plate implantation was 11.35 years (SD 3.29).Of those with femoral deformities, 85% of the patients finished the treatment and of those, 70% were corrected to standard alignment, while 14% have not yet achieved correction, and are still growing.Of those with tibial deformities, 75% of the patients finished the treatment and of those 80% were corrected to standard alignment, while 25% have not yet achieved correction and are still growing.The calculated rate of correction was 0.77°/month for the femur and 0.79°/month for the tibia.In terms of complications, the overall rate of infection was 1.48%. In three patients (0.55%) screw breakage was recorded.Factors found to significantly influence the amount of correction were age at plate implantation and direction of deformity. CONCLUSION: Temporary hemiepiphysiodesis takes the advantage of physiological physeal growth to effectively treat angular deformities. Success of treatment is influenced by the age of the patient at plate implantation and direction of deformity. LEVEL OF EVIDENCE: IV.

Tibial lengthening over intramedullary nails: A matched case comparison with Ilizarov tibial lengthening.

OBJECTIVES: The purpose of this study was to compare the results and complications of tibial lengthening over an intramedullary nail with treatment using the traditional Ilizarov method. METHODS: In this matched case study, 16 adult patients underwent 19 tibial lengthening over nails (LON) procedures. For the matched case group, 17 patients who underwent 19 Ilizarov tibial lengthenings were retrospectively matched to the LON group. RESULTS: The mean external fixation time for the LON group was 2.6 months and for the matched case group was 7.6 months. The mean lengthening amounts for the LON and the matched case groups were 5.2 cm and 4.9 cm, respectively. The radiographic consolidation time in the LON group was 6.6 months and in the matched case group 7.6 months. Using a clinical and radiographic outcome score that was designed for this study, the outcome was determined to be excellent in 17 and good in two patients for the LON group. The outcome was excellent in 14 and good in five patients in the matched case group. The LON group had increased blood loss and increased cost. The LON group had four deep infections; the matched case group did not have any deep infections. CONCLUSIONS: The outcomes in the LON group were comparable with the outcomes in the matched case group. The LON group had a shorter external fixation time but experienced increased blood loss, increased cost, and four cases of deep infection. The advantage of reducing external fixation treatment time may outweigh these disadvantages in patients who have a healthy soft-tissue envelope.Cite this article: J. E. Herzenberg. Tibial lengthening over intramedullary nails: A matched case comparison with Ilizarov tibial lengthening. Bone Joint Res 2016;5:1-10. doi: 10.1302/2046-3758.51.2000577.

Life- and limb-threatening infections following the use of an external fixator.

External fixation is widely used in orthopaedic and trauma surgery. Infections around pin or wire sites, which are usually localised, non-invasive, and are easily managed, are common. Occasionally, more serious invasive complications such as necrotising fasciitis (NF) and toxic shock syndrome (TSS) may occur. We retrospectively reviewed all patients who underwent external fixation between 1997 and 2012 in our limb lengthening and reconstruction programme. A total of eight patients (seven female and one male) with a mean age of 20 years (5 to 45) in which pin/wire track infections became limb- or life-threatening were identified. Of these, four were due to TSS and four to NF. Their management is described. A satisfactory outcome was obtained with early diagnosis and aggressive medical and surgical treatment. Clinicians caring for patients who have external fixation and in whom infection has developed should be aware of the possibility of these more serious complications. Early diagnosis and aggressive treatment are required in order to obtain a satisfactory outcome.

The effect on mechanical axis deviation of femoral lengthening with an intramedullary telescopic nail.

Internal lengthening devices in the femur lengthen along the anatomical axis, potentially creating lateral shift of the mechanical axis. We aimed to determine whether femoral lengthening along the anatomical axis has an inadvertent effect on lower limb alignment. Isolated femoral lengthening using the Intramedullary Skeletal Kinetic Distractor was performed in 27 femora in 24 patients (mean age 32 years (16 to 57)). Patients who underwent simultaneous realignment procedures or concurrent tibial lengthening, or who developed mal- or nonunion, were excluded. Pre-operative and six-month post-operative radiographs were used to measure lower limb alignment. The mean lengthening achieved was 4.4 cm (1.5 to 8.0). In 26 of 27 limbs, the mechanical axis shifted laterally by a mean of 1.0 mm/cm of lengthening (0 to 3.5). In one femur that was initially in varus, a 3 mm medial shift occurred during a lengthening of 2.2 cm. In a normally aligned limb, intramedullary lengthening along the anatomical axis of the femur results in a lateral shift of the mechanical axis by approximately 1 mm for each 1 cm of lengthening.

Mechanical failure of the Intramedullary Skeletal Kinetic Distractor in limb lengthening.

Between October 2001 and September 2009 we lengthened 242 lower-limb segments in 180 patients using the Intramedullary Skeletal Kinetic Distractor (ISKD). Mechanical failure was defined either as breakage of the ISKD or failure of the internal mechanism to activate. Retrieved nails which failed mechanically were examined by the manufacturer for defects. In all, 15 ISKDs in 12 patients (13 limbs) failed mechanically representing an overall failure rate of 6.2%, with fracture of the device occurring in ten of the 15 failures. Two nails in one patient failed to lengthen and had to be replaced. The manufacturer detected an error in the assembly of the nail, which prompted a wide recall. One nail jammed after being forcefully inserted, and two nails failed to lengthen fully. Lengthening was achieved in all 12 patients, although three required a second operation to exchange a defective nail for a new, functioning device. The ISKD is a complex mechanical device which lengthens by the oscillation of two telescopic sections connected by a threaded rod. The junction between these sections is surrounded by a keyring collar. This keyring collar is the weakest part of the device.

Maternal attitudes towards prenatal diagnosis of idiopathic clubfoot.

OBJECTIVES: To examine maternal attitudes towards prenatal diagnosis of idiopathic clubfoot and to determine the incidence of false-negative ultrasound examinations. METHODS: Surveys were mailed to mothers of patients with clubfoot born between 2000 and 2007 who were treated at either Sinai Hospital of Baltimore or Orthopaedic Hospital Speising. Exclusion criteria were underlying syndrome, genetic abnormality and multiple pregnancy. The survey asked the mother whether she had had any ultrasound examinations before her child was born, whether any of these had shown clubfoot, and whether she would have preferred to find out about her child's clubfoot before birth or after birth. RESULTS: Mothers completed 220 (USA, 105 surveys; Austria, 115 surveys) of 401 mailed surveys. The prenatal detection rate was 60% in the USA compared with 25% in Austria (P = 0.001). Overall, 74% of mothers indicated a preference for prenatal diagnosis and 24% indicated a preference for postnatal diagnosis of the condition. Of 92 patients diagnosed prenatally, 96% of mothers indicated a preference for a prenatal diagnosis. Of 128 patients diagnosed postnatally, 58% of mothers indicated a preference for prenatal diagnosis, 38% for postnatal diagnosis and 4% were undecided. CONCLUSIONS: The diagnosis of clubfoot is still often missed during routine ultrasound examination. When a prenatal diagnosis is made, most mothers appreciate having this information. However, when prenatal diagnosis is missed, a significant proportion of mothers seem to accept the false-negative diagnosis retrospectively.

Multiplier method for predicting limb-length discrepancy.

BACKGROUND: In patients with a congenital or developmental limb-length discrepancy, the short limb grows at a rate proportional to that of the normal, long limb. This is the basis of predicting limb-length discrepancy with existing methods, which are complicated and require multiple data points. The purpose of our study was to derive a simple arithmetic formula that can easily and accurately predict limb-length discrepancy at skeletal maturity. METHODS: Using available databases, we divided the femoral and tibial lengths at skeletal maturity by the femoral and tibial lengths at each age for each percentile group. The resultant number was called the multiplier. Using the multiplier, we derived formulae to predict the limb-length discrepancy and the amount of growth remaining. We verified the accuracy of these formulae by evaluating two groups of patients with congenital shortening who were managed with epiphysiodesis or limb-lengthening. We also calculated and compared the multipliers for other databases according to radiographic, clinical, and anthropological lower-limb measurements. RESULTS: The multipliers for the femur and tibia were equivalent in all percentile groups, varying only by age and gender. Because congenital limb-length discrepancy increases at a rate proportional to growth, the discrepancy at maturity can be calculated as the current discrepancy times the multiplier for the current age and the gender. This calculation can be performed with use of a single measurement of limb-length discrepancy. For progressive developmental (noncongenital) discrepancies, the discrepancy at skeletal maturity can be calculated as the current discrepancy plus the growth inhibition times the amount of growth remaining. The timing of the epiphysiodesis can also be calculated with the multiplier. The predictions made with use of the multiplier method correlated well with those made with use of the Moseley method as well as with the actual limb-length discrepancy in both the limb-lengthening and epiphysiodesis groups. The multipliers derived from the radiographic, clinical, and anthropological measurements of femora and tibiae were all similar to each other despite differences in race, ethnicity, and generation. CONCLUSIONS: The multiplier method allows for a quick calculation of the predicted limb-length discrepancy at skeletal maturity, without the need to plot graphs, and is based on as few as one or two measurements. This method is independent of percentile groups and is the same for the prediction of femoral, tibial, and total-limb lengths. The multiplier values are also independent of generation, height, socioeconomic class, ethnicity, and race. We verified the accuracy of this method clinically by evaluating patients who had been managed with limb-lengthening or epiphysiodesis. The method was also comparable with or more accurate than the Moseley method of limb-length prediction.

The adaptation of perimuscular connective tissue during distraction osteogenesis.

It is not known whether the decreased range of motion observed during distraction osteogenesis results from the lack of adaptation of muscle or from fibrosis in the perimysium. The adaptation of the perimysium in the tibialis anterior muscle in skeletally immature rabbits using two distraction regimens (0.7 and 1.4 mm/day with 15% lengthening) was characterized. The resulting data indicate that during distraction osteogenesis, the muscle adapts by reorganization of its connective tissue. At a lengthening rate of 1.4 mm/day, there is perimysial fibrosis without major cellular pathologic abnormalities in the muscle fibers. The increase in perimysial thickness is characterized by an increase of collagen Type I. In addition, collagen Type I is deposited around the endomysium. The increase in total collagen and its cross-linking are dependent on the lengthening rate. The faster lengthening rate also leads to a significant decreased passive plantar flexion. Supplemental growth of the tibia was not observed, and a lack of adaptation in the muscle (based on resting length) was not seen. Together, the data suggest that decreased range of motion during distraction osteogenesis may be a function of the adaptation of the perimysium rather than of the muscle fibers.

Growth patterns after lengthening of congenitally short lower limbs in young children.

The purpose of this study was to assess growth patterns after lengthening of the congenitally short femur or tibia in children younger than 6 years. Twenty such children underwent 28 bone segment lengthenings (13 femora and 15 tibiae) by distraction osteogenesis. Our results show that femoral lengthening in children younger than 6 years does not lead to growth inhibition, whereas isolated femoral lengthening may be associated with growth stimulation. Isolated tibial lengthening in children younger than 6 years does not lead to growth inhibition, whereas simultaneous femoral and tibial lengthening or two tibial lengthenings in close succession can lead to tibial growth inhibition.

Accurate determination of cast weight for neonates with clubfoot.

The purpose of this study was to determine changes in cast weight during the first 48 hours after application so that the true weight of a neonate can be estimated without the need for removing the cast. Five types of cast materials were compared. Cast weight measurements were obtained before and after application and at intervals during 48 hours. Final cast weight averaged 107.5% of dry weight for plaster and 99% of dry weight for synthetic cast materials. For very low birth weight infants, the difference between the initial wet weight of plaster of Paris and its final dry weight may be significant for calculating drug and fluid dosages. The weight of an infant can now be calculated without the necessity of cast removal.

Muscle regeneration and fiber-type transformation during distraction osteogenesis.

The successful outcome of distraction osteogenesis depends in part on the adequate adaptation of the surrounding soft tissue. We characterized the adaptation of the tibialis anterior during distraction osteogenesis at different rates (0.7 and 1.4 mm/day) and amounts (15 and 30%) of lengthening. We documented the increased expression of neonatal and slow myosin heavy chain in the tibialis anterior of skeletally immature rabbits. There was neither expression of neonatal myosin heavy chain in the experimental soleus or in the slow muscle fibers of the tibialis anterior nor increased expression of slow myosin heavy chain in the soleus or gastrocnemius. The increased amount of neonatal myosin heavy chain was concentrated in the distal half of the muscle, whereas the increase in the number of fibers that were labeled with antibodies to slow myosin occurred to the same extent throughout the tibialis anterior. Electrophysiological methods showed that the tibialis anterior was functionally intact during and after distraction osteogenesis. We concluded that in the tibialis anterior of young, skeletally immature animals, distraction osteogenesis seems to induce a recapitulation of the developmental process without leading to functional changes. In addition, during distraction osteogenesis, a fiber-type transformation occurs similar to that observed in models of muscle overloading.

Improvement in gait parameters after lengthening for the treatment of limb-length discrepancy.

BACKGROUND: Patients who have limb-length discrepancy demonstrate an altered gait pattern or a limp. The purpose of this prospective study was to compare the objective gait parameters for the shorter lower limb with those for the longer lower limb before and after lengthening and to compare these data with those for a group of twenty subjects who had no limb-length discrepancy. METHODS: Eighteen patients had equalization of limb length to within one centimeter. We analyzed the stance time, the second peak of the vertical ground-reaction-force vector, and the rate of loading with use of two force-plates arranged in a series. RESULTS: The difference in the mean stance times between the shorter and longer limbs before lengthening was 12 percent, whereas that after lengthening was 2.4 percent; the difference between the values before and after lengthening was significant (p<0.001). The difference in the stance times between the limbs of the patients who did not have limb-length discrepancy was 2 percent. Preoperatively, the mean second peak was 104 percent of body weight for the shorter limb compared with 116 percent for the longer limb; this difference was significant (p<0.001). After lengthening, the mean second peak for the shorter limb increased to 113 percent of body weight. The difference in the means for the second peak before and after lengthening was significant (p<0.001). With the numbers available, no significant difference was detected in the means for the second peak between the shorter and longer limbs after lengthening (p = 0.12). CONCLUSIONS: This study shows that lengthening of the shorter limb of patients who have limb-length discrepancy can normalize symmetry of quantifiable stance parameters and eliminate a limp.

The load applied to the foot in a patellar ligament-bearing cast.

The purpose of this study was to determine whether a patellar ligament-bearing cast reduces the load applied to a foot in a cast. In a study of ten people who had no history of gait abnormalities, disease involving the motor system, or deformities of the lower extremities, we compared the load applied to the plantar aspect of a foot in a cast (as detected with F-Scan computer-monitored pedobarographic sensors) with the total load that an extremity in a cast receives relative to the ground (as detected with force-plates). Six trials were completed three times by each person. The trials consisted of walking (1) while wearing regular shoes; (2) with a patellar ligament-bearing cast on one leg; (3) with a patellar ligament-bearing cast and an overlying soft knee brace, locked in full extension, on the leg; (4) with only a below-the-knee cast on the leg; (5) with a below-the-knee cast and an overlying knee brace, locked in full extension, on the leg; and (6) with only a knee brace, locked in full extension, on the leg. The loads at peak heel-strike for all three trials were averaged and normalized to body weight. The load on the plantar aspect of the foot, as compared with the total load, was reduced a mean of 11 percent when the patellar ligament-bearing cast was worn alone, and it was reduced a mean of 26 percent when the patellar ligament-bearing cast was used with an overlying knee brace locked in full extension. This difference was significant (p = 0.007). With the numbers available, we could not detect a significant difference between the reduction in load when a patellar ligament-bearing cast was worn alone compared with that when a below-the-knee cast was worn alone or between the reduction when a below-the-knee cast was worn alone compared with that when a below-the-knee cast was used with a knee brace (p = 0.3). In conclusion, we could not demonstrate a significant reduction in the load on the foot when a patellar ligament-bearing cast was used in a traditional fashion; however, a significant (p = 0.007) reduction in load was found when a knee brace locked in full extension was worn in addition to the patellar ligament-bearing cast.

Detection of nerve entrapment during limb lengthening by means of near-nerve recording.

Eight patients undergoing limb lengthening by the Ilizarov method had near-nerve needle electrode conduction studies when they developed clinical signs of nerve entrapment. The near-nerve technique was chosen because it is highly sensitive to configurational changes which appear in the action potential as injury occurs. In 10 out of 13 symptomatic limbs the near-nerve potential was found to be abnormally small and its usually smooth contour had become notched and irregular. In the remaining 3 limbs the potentials were normal initially but became abnormal as further constriction of the nerve took place. Nerve potentials remained normal in size and shape in asymptomatic limbs undergoing lengthening and were not altered by application of the Ilizarov frames themselves. The near-nerve technique proved useful in the early detection of nerve injury in these patients and thus enabled surgical intervention before nerve damage had become permanent.

Leg lengthening in children.

Leg lengthening techniques, imported from Russia and Europe, have developed during the past 10 years in North America and have matured to become an accepted method of treating leg length discrepancy. The use of these techniques for stature lengthening in dwarfism is somewhat less widespread. A review of published reports indicates a maturation in the field of leg lengthening, with more focused studies on larger cohorts of patients having the same pathology. Long-term follow-up studies are forthcoming, and there is still extensive room for basic research. Precise indications and limits for lengthening in femoral hypoplasia and fibular hemimelia are unclear, and await additional reporting. Future research needs to include outcome studies, hardware improvements, implantable lengthening devices, and a better understanding of the basic science behind lengthening of both bone and soft tissues.