This article describes a simple method of confirming intraarticular placement of the needle tip while performing arthrography or arthrocentesis. A length of i.v. tubing attached to a three-way stopcock is filled with normal saline ensuring that a single bubble of air is present in the tubing. After introducing the needle into the joint, the tubing is connected to the needle. The stopcock is opened to the air and then traction is applied to the limb. As the joint is distracted by traction a small forward movement of the air bubble confirms intraarticluar palcement of the needle tip.

The technique described is simple and elegant and is likely to be very useful.

Data on 452 patients with 509 affected knees from 44 hospitals were analysed. 154 of the 509 knees were treated conservatively, while 355 were treated surgically (many with multiple operations). 198 knees initially presented with favourable features (no effusion, diameter of lesion (<)20 mm and no gross dissection on imaging) while 311 had unfavourable features (one or more of these three features was unfavourable). 51% of the lesions were on the lateral side of the medial femoral condyle (typical site) while various other locations were encountered in the remaining knees. The analysis showed that among patients with favourable features, those that were treated conservatively fared better than those who were operated. In patients with signs of dissection, the results were better after operative treatment.

The data on 454 patients were collated from 44 hospitals. This clearly indicates that very little meaningful information could have been generated fom any single centre on account of the small number of cases. Compilation of data from several centres enabled the EPOS to provide extremely useful guidelines of management. The Editors chose this article to emphasise the value of multicentre studies. This multicentre study was conducted by the European Pediatric Orthopedic Society.

We urge members to take note of this and also the suggestions for such studies alluded to in the Editorial and in the News and Notes section of this issue of POSITIVE.

The authors reviewed 138 patients with a diagnosis of septic arthritis based on aspiration of synovial fluid which was purulent with a cell count of >50,000 comprising >80% polymorphs. Only 30% of cultures performed on these aspirates grew organisms. The culture-negative cases had the same clinical features and synovial fluid characteristics as the culture-positive cases. The authors recommend that culture-negative cases with clinical features of septic arthritis should be treated aggressively on the same lines as the culture-positive cases.

The authors draw attention to an important issue. Treatment of septic arthritis should be based primarily on the clinical features. Withholding an arthrotomy for want of a positive culture is unwise. It is also well known that imaging has a very limited role in the diagnosis of acute septic arthritis. The mainstay of diagnosis of septic arthritis is still clinical examination.

Eleven patients with DDH diagnosed at a mean age of 7 years who had no treatment in childhood were followed-up for 40 years. Nine of the 11 patients had bilateral dislocations. None developed avascular necrosis. The clinical and functional results were satisfactory despite poor radiographic appearances. These patients achieved a better quality of life than many patients of a similar age who had undergone surgical procedures in late childhood to reduce dislocated hips.

At the first meeting of POSI, Dr. In-Young Ok of Korea had presented his results of reduction of hips in older children and adolescents. His results were truly remarkable. However, such impressive results are difficult to achieve. This is particularly true if the surgeon performs this type of surgery on an occasional basis. It is worth taking note of the observation made in the paper of Crawford and colleagues that in the long-term, the results of leaving a hip unreduced in the older child may be better than undertaking elaborate surgery. In the light of this, it may be quite justified to recommend that unreduced DDH in the older child be left untreated especially in bilateral cases.

Opinions regarding this issue are invited from members.

Ultrasonography of the hip was performed on 115 children with hip pain. Hip distension of over 2mm which is diagnostic of an effusion was diagnosed accurately. Ultrasound examinations were repeated every week for six weeks. In children with transient synovitis the effusion persisted for a mean period of 16 days and, in 63% of cases, disappeared completely within 14 days. In nine hips the effusion persisted throughout the six week period. All these hips eventually developed Perthes' disease.

This study is of practical value as it helps to distinguish an impending Perthes' disease from transient synovitis. If, in the absence of plain radiographic evidence of Perthes' disease, an effusion persists for over six weeks, a tentative diagnosis of Perthes' disease may be entertained. Only then would the clinician need to proceed to any further investigation for the confirmation of Perthes' disease.

The outcome of treatment of 16 femoral neck fractures in 14 children were reviewed. Non-operative management was undertaken for all undisplaced stable fractures while all displaced fractures were treated by hip aspiration, closed reduction and internal fixation under fluoroscopic control within 24 hours of the injury. In three patients open reduction was needed. Cannulated screws were used to fix the fractures taking care to avoid crossing the growth plate except for transepiphyseal fractures. In 13 patients the fractures united without any delay. Avascular necrosis did not occur in any case.

This study reports a remarkably low incidence of complications following femoral neck fractures in children, unlike most earlier reports. A closer look at the possible reasons for the good results is needed. In all probability three factors contributed to the successful outcome. They were, the timing of surgical intervention, the routine aspiration of the hip and the type of internal fixation used. In all patients with displaced fractures, aspiration of the hip was performed to reduce the intra-capsular pressure. This procedure appears to be an essential part of the treatment of femoral neck fractures in children. The patients underwent aspiration and surgery within 24 hours. This again, is of vital importance as prolonged tamponade due to a tense haemarthrosis would jeopardise the blood supply of the femoral head. Both these factors would have contributed positively to the avoidance of avascular necrosis. Stable fixation of the fractures with canulated screws seems to have facilitated union.

27 patients between the ages of 4 and 8 years who underwent redo surgery for clubfoot had a complete soft tissue release combined with a calcaneocuboid fusion. 26 feet had a long-term good result. The authors recommend this as the procedure of choice for relapsed clubfeet in this age group.

The combination of a soft tissue release with fusion of the calcaneocuboid joint is the what was recommended by Dillwyn Evans in 1961 for correcting clubfeet in children between 4 and 8 years of age. The present authors also performed this procedure in the same age group recommended by Evans with good results.

Arthrograms were performed on 133 hips after closed reduction by overhead traction. The patients were followed up till skeletal maturity. The thickness of soft tissue interposition at the acetabular floor as shown on the arthrograms was measured. Even marked soft tissue interposition disappeared by the age of 5 years in 71% of cases. The final radiographs at skeletal maturity of hips in which soft tissue interposition disappeared, were indistinguishable from hips in which there was no soft tissue interposition. If there was more than 3.5mm of soft tissue interposition, secondary surgery was often required. All children in whom the soft tissue interposition did not disappear by 5 years required further surgery and their results were clearly poorer than those of children in whom the interposition had resolved.

It was generally accepted that if an arthrogram after closed reduction showed evidence of soft tissue interposition, an open reduction and removal of the interposed soft tissue was mandatory. This study challenges this concept. It is reassuring to note that a minor degree of soft tissue interpostion is inconsequential provided the hip remains stable.

D'Souza H, Arjooris A, Chawar GS. Wadia Hospital, Mumbai, India. Journal of Pediatric Orthopaedics 1998; 18: 760-4.

Johari AN, Sinha M. Grant Medical College & Sir JJ Group of Hospitals, Mumbai, India.Journal of Pediatric Orthopaedics - B 1999; 8:84-7.

D'Souza H, Shah NM.Children's Orthopaedic Hospital, Mumbai, India. Journal of Pediatric Orthopaedics 1999; 19: 215-22.

The authors would be pleased to send copies of their articles to any member who requests them.

The Role of Intramedullary Rodding in Osteogenesis Imperfecta

As long as a cure for osteogenesis imperfecta remains elusive, treatment would necessarily have to be directed towards minimising the frequency of fractures, thereby improving the quality of life. Correction of deformities of long bones and intramedullary rodding is one option currently available for achieving this aim. However, intramedullary rodding in osteogenesis imperfecta is not without complications (1, 2, 4-7,10-12), and some of these complications necessitate further surgery. It is, therefore, necessary to evaluate whether surgery, often repeated, does improve the quality of life sufficiently in children with osteogenesis to justify its use.

Intramedullary roddding in skeletally immature children with osteogenesis may be performed with:

• 1) a single non-elongating rod
• 2) a telescoping rod (which elongates as the bone grows)
• 3) double Rush rods

The telescoping rod is in reality a tube with a rod within it. Both the outer tube and the inner rod have a T-piece at one end. The T-piece of one component of the rod is placed proximal to the growth plate at the proximal end of the bone while the T-piece of the other component of the nail is placed distal to the distal growth plate of the bone. As a consequence, the inner rod slides out of the outer tube as the bone grows in length. Once the inner rod slides out completely from the outer tube the rod needs to be changed.

Evidence from literature clearly shows that intramedullary rodding of long bones in osteogenesis imperfecta greatly improves the quality of life (1, 2, 4-7, 10, 12, 13). The dramatic reduction in the frequency of fractures alone would justify intramedullary rodding. Several of these studies have also shown that the ambulatory capacity (3) of these children improve following intramedullary rodding.

The value of intramedullary rodding in osteogenesis imperfecta would be even greater if it is possible to:

• 1) avoid complications requiring re-operations and
• 2) increase the interval between primary rodding and re-rodding.

A closer look at complications following rodding shows that several of them are related to the type of implant used. In order to achieve the aim of minimising the re-operation rate it would be necessary to identify the type of rod that has the fewest complications.

Studies show that the frequency of complications requiring re-operations and change of the rod is less with telescoping rods than with non-elongating rods. Among the rod-related complications seen after telescoping rodding, T-piece separation frequently seen with the Bailey-Dubow rod (2, 4-6, 8, 9) is one that has been overcome with the Sheffield rod. But problems of intra-articular and metaphyseal migration of the T-piece continue to be a problem even with the Sheffield modification of the Bailey-Dubow rod. As would be expected, metaphyseal migration occurs more commonly when the T-piece is placed in the metaphyseal half of the epiphysis while intra-articular migration occurs more frequently when it is placed in the articular half of the epiphysis. So an attempt must be made to anchor the T-piece in the centre of the epiphysis.

The placement of the rod in the centre of the medullary cavity parallel to the long axis of every fragment of the bone appears to be essential to minimise the risk of extra-cortical migration. There should be no hesitation to perform additional osteotomies to facilitate such precise placement of the rod within the medullary cavity of each fragment.

Marafioti and Westin (6) noted that at re-operation the articular cartilage over the area where the T-piece was originally introduced may appear “smooth and normal with no indication of where the T-piece might have been seated”. Consequently, it may be difficult to locate the buried T-piece within the epiphysis. On account of this, Nicholas and James (8) recommended that only one component of the elongating rod be exchanged when re-rodding is required. If the the proximal femoral T-piece is not buried in the trochanter and the distal tibial T-piece is not fixed within the tibial epiphysis, only these components need to be changed. This would avoid an arthrotomy of the knee at the time of rod change, and also avoid the risk of excessive articular damage while trying to locate the buried T-piece.

A change of the rod is needed either when the bone outgrows the rod or for rod-related complications. It has been shown that the interval between primary rodding and re-rodding is significantly longer with elongating rods than with non-elongating rods (1, 6).

The results from the literature cited here indicate that the frequency of complications is least with the Sheffield telescoping rod. The interval between primary rodding and rod change is also greater with telescoping rods. However, the prohibitive cost of telescoping rods unfortunately prevents its use in several patients in our country. Even when the patient can afford telescoping rods it will not be possible to have 25 to 30 rods of various sizes available at the time of surgery as recommended by Lang-Stevenson and Sharrard (4). It then becomes necessary to estimate the appropriate length and thickness of the rod pre-operatiively and order one rod for each bone. It is possible to make a sufficiently accurate estimate of the rod size from pre-operative radiographs to avoid the need for a large assortment of rods to be available at the time of surgery.

A very cost-effective alternative to telescoping rodding is the use of two Rush rods (8), one introduced from the proximal end of the bone while the other is introduced from the distal end of the bone. The hooks are embedded in the epiphyses in the same location as the T-pieces of telescoping rods. This would be an excellent option for patients in our country.

In conclusion, intramedullary rodding of long bones of children with osteogenesis imperfecta improves the quality of life considerably by reducing the frequency of fractures and by improving their ambulatory capacity. Complications of rodding requiring re-operations can be minimised by careful attention to technical details of pre-operative rod selection and intra-operative rod placement. Telescoping rods are superior to non-elongating rods in terms of greater longevity and fewer complications requiring re-operations.

1. Bailey RW, Dubow HI. Evolution of the concept of an extensible nail accommodating to normal longitudinal bone growth: clinical considerations and implications. Clin Orthop 1981; 159: 157-70.
2. Gamble JG, Strudwick WJ, Rinsky LA, Bleck EE. Complications of intramedullary rods in osteogenesis: Bailey-Dubow rods versus non-elongating rods. J Pediatr Orthop 1988; 8: 645-9.
3. Hoffer MM, Bullock M. The functional and social significance of orthopedic rehabilitation of mentally retarded patients with cerebral palsy. Orthop Clin North Am 1981; 12: 185-91.
4. Lang-Stevenson AI, Sharrard WJW. Intramedullary rodding with Bailey-Dubow extensible rods in osteogenesis imperfecta: an interim report of results and complications. J Bone Joint Surg (Br) 1984; 66-B:     227-32.
5. Luhmann SJ, Sheridan JJ, Capelli AM, Schoenecker PL. Management of lower extremity deformities in osteogenesis imperfecta with extensible intramedullary rod technique: A 20-year experience. J Pediatr     Orthop 1998; 18: 88-94.
6. Marafioti RL, Westin GW. Elongating intramedullary rods in the treatment of osteogenesis imperfecta. J Bone Joint Surg (Am) 1977; 59-A: 467-72.
7. Middleton RWD. Closed intramedullary rodding for osteogenesis imperfecta. J Bone Joint Surg (Br) 1984; 66-B: 652-5.
8. Nicholas RW, James P. Telescoping intramedullary stabilization of the lower extremities for severe osteogenesis imperfecta. J Pediatr Orthop 1990; 10: 219-23.
9. Porat S, Heller E, Seidman DS, Meyer S. Functional results of operation in osteogenesis imperfecta: Elongating and non-elongating rods. J Pediatr Orthop 1991; 11: 200-3.
10. Stockley I, Bell MJ, Sharrard WJW. The role of expanding intramedullary rods in osteogenesis imperfecta. J Bone Joint Surg (Br) 1989; 71-B: 422-7.
11. Wilkinson JM, Scott BW, Clarke AM, Bell MJ. Surgical stabilisation of lower limbs in osteogenesis imperfecta using the Sheffield telescoping intramedullary rod system. J Bone Joint Surg (Br) 1998; 80-B:     999-1004.
12. Williams PF. Fragmentation and rodding in osteogenesis imperfecta. J Bone Joint Surg (Br) 1965; 47-B: 23-31.
13. Zionts LE, Ebramzadeh E, Stott NS. Complications in the use of the Bailey-Dubow extensible nail. Clin Orthop 1998; 348: 186-95

This is the first part of a two-part article which outlines the options available for bracing in polio. It was felt that orthotic services in the country need to improve a great deal. This article is an attempt to create an awareness about orthotics. If any member would like to get more information regarding techniques of fabrication of thermoplastic orthoses referred to in this article, please feel free to contact the Editor who will furnish addresses of centres where these orthoses are routinely fabricated.

A child with severe residual paralysis following polio finds it impossible to ambulate on account of paralysis of muscles that are essential for locomotion. The muscle paralysis compromises the ability to propel the limb forwards during the swing phase of gait and may also make the limb unstable during the stance phase of gait. An orthotic appliance can stabilise joints rendered unstable by muscle paralysis. However, the additional weight of the appliance and the enforced immobility of joints brought about by the orthosis often renders purposeful ambulation in the community difficult or impossible.

It, therefore, becomes necessary to define in clearer terms the pre-requisites of lower limb orthotics in polio.

The orthosis must:

• 1. Stabilise the lower limb, which is a multi-segmented structure, during the stance phase of gait and prevent it from collapsing
• 2. Facilitate a method of propulsion that is as economical as possible in terms of energy consumption.

This can be achieved if two basic principles are borne in mind viz.

• 1. The orthotic device should be as light as possible.
• 2. Any joint that can be possibly left free without compromising stability during ambulation should not be rendered immobile by the orthosis.

The options available for restoring stability at joints include surgical stabilisation and orthotic stabilisation.

Wherever possible it is advisable to avoid the permanent use of orthoses. This may not be possible in the skeletally immature patient, but every effort must be made to achieve this goal in the adult patient. The choice of treatment would depend on whether the instability at a joint is unidirectional or multidirectional, the age of the patient and whether permanent abolition of motion at a joint by arthrodesis is an acceptable option or not.

Based on these considerations an algorithm for dealing with instability of the lower limb in polio can be applied.

If there is unidirectional instability at a joint, can the instability be corrected by any one of the following surgical orptions?

• Tendon transfer     eg. Tibialis posterior transfer for a foot drop
• Osteotomy      eg. Supracondylar extension osteotomy of the femur for quadriceps paralysis
• Bone block      eg. Posterior bone block for foot drop
• Tenodesis      eg. Westin's tenodesis for a calcaneus deformity

If one of these procedures can be performed, an orthosis can be avoided.

If, however, none of these options are feasible, orthotic stabilisation is indicated.

If there is multidirectional instability at a joint, is the patient skeletally immature or skeletally mature?

In skeletally immature patients orthotic stabilisation is indicated.

In skeletally mature patients will an arthrodesis be accepted? If not, orthotic stabilisation is indicated.

It is clear that bracing is indicated for unidirectional instability only if cannot be effectively managed by appropriate surgery. However, bracing plays a more important role when there is multidirectional instability at a joint.

An unstable joint can be stabilised by abolishing all movement at the joint. Incorporating a lock in the joint of the orthosis can do this. However, immobilisation of the hip, knee or ankle increases the energy consumption during ambulation. This was demonstrated quite clearly by the work of Ralston in 1965. Mere immobilisation of both ankles of normal healthy male subjects increased energy consumption by 9%. Immobilisation of the knee not only increased the energy expenditure at all speeds, but also limited the speed of walking to half the speed of a normal individual. While the increase in energy expenditure may seem inconsequential in a healthy person, it may be unacceptable in a disabled individual. Keeping this in mind we can define the role of orthotic stabilisation at each joint.

Stabilisation of the foot and ankle

The flail foot: (Sagittal plane instability at the ankle and coronal plane instability at the subtalar joint)

The orthosis must prevent

• a. plantarflexion during the swing phase of gait
• b. uncontrolled excessive dorsiflexion during the latter half of the stance phase of gait
• c. valgus and varus instability during the stance phase of gait.

Options:

• 1. below knee calipers with double irons with no ankle joints
• 2. below knee calipers with double irons with limited motion joints
• 3. thermoplastic ankle-foot orthosis with trim lines passing anterior to the malleoli.

The thermoplastic orthosis would be the lightest of the three. The below knee caliper with limited motion ankle joints has the advantage of permitting a small range of movement at the ankle. This limited motion facilitates plantar flexion and dorsiflexion during the different parts of the stance phase. The gait pattern is therefore, much better than when motion at the ankle is totally abolished.

Varus or valgus instability at the hind foot: (coronal plane instability)

Varus or valgus instability usually occurs at the subtalar joint on account of paralysis of the evertors or invertors. Occasionally instability at the ankle joint may occur due to stretching of the collateral ligaments.

• a. control varus or valgus instability at the subtalar or ankle joint
• b. permit free dorsiflexion and plantarflexion.

• 1. below knee caliper with a medial iron and a lateral T-strap and a free motion ankle joint
• 2. thermoplastic ankle-foot orthosis with trim lines passing anterior to the malleoli.

• 1. below knee caliper with a lateral iron and a medial T-strap and a free motion ankle joint
• 2. thermoplastic ankle-foot orthosis with trim lines passing anterior to the malleoli.

The thermoplastic ankle-foot orthosis is cosmetically more appealing than the traditional below knee caliper. However, the need to move the trim line of the orthosis anterior to the malleoli makes the orthosis quite rigid with virtually no motion at the ankle joint.

Foot drop: (sagittal plane instability)

• a. restrict plantarflexion during the swing phase of gait in order to provide adequate clearance of the toes.
• b. not restrict the freedom of passive dorsiflexion during stance.

• 1. Below knee caliper with 90 degree foot drop stop
• 2. Below knee caliper with 90 degree foot drop stop and dorsiflexion assist
• 3. Thermoplastic ankle foot orthosis with trim lines running posterior to the ankle joint.

The thermoplastic orthosis is the most appealing cosmetically. Passive dorsiflexion is possible during the latter part of the stance phase of gait. If a traditional caliper is preferred, the incorporation of a joint with a dorsiflexion assist makes the gait pattern better than when a 90 foot drop stop alone is used.

Calcaneus: (sagittal plane instability)

• a. restrict uncontrolled dorsiflexion of the foot during the stance phase of gait.

• 1. Below knee caliper with reversed 90 degree foot drop stop
• 2. Thermoplastic ankle foot orthosis.

The next POSI Conference will be held in Mumbai between 5th and 8th March 2000

For further details contact :

Children's Orthopaedic Centre, 7 Jilani Manzil, Gokhale Road North,
Dadar (W), MUMBAI 400 028
Fax: 22 444 5599, Email: posi2000@mailandnews.com

The Department of Orthopaedics at Kasturba Medical College invites applications for a one year Fellowship in Paediatric Orthopaedics. The Fellowship offers an exposure to a broad range of Paediatric Orthopaedic diseases. The fellow will receive a monthly stipend and a certificate from the Manipal Academy of Higher Education ( A Deemed University ) on completion of the Fellowship.

For further information contact : Dr.Benjamin Joseph, Paediatric Orthopaedic Service, Department of Orthopaedics, Kasturba Hospital, Manipal 576 119, Karnataka. The last date for submitting applications is July 15, 2000.

Responses to Clubfoot Questionnaire

A questionnaire on the treatment of clubfoot had been included in the last issue of POSITIVE. It was extremely disheartening to note that only 18 completed questionnaires were received from members. We would urge the members who have not yet sent in their responses to kindly do so. We cannot ever embark on any meaningful multi-centre study unless we are disciplined enough to actively participate in sharing of information. This exercise was an attempt to collate trends in the methods of treatment of clubfoot, analyse the data and then define possible areas of future research.