Case of the Week 25/9/97: What people said...

I will correct first all bone deformity such femoral anteversion or tibial torsion and loss of the bony rigidity at the feet. then I will transfer the rectus femoris to the gracilis to improve clearence in swing, and Strayer to lengthen the gastrocnemius, in order to improve clearence in swing and stability in stance.

marcrupg502@cantvnw1.cantv.net (Marcel Rupcich)

Thanks to Marcel Rupcich for getting the ball rolling. Whilst I agree, I wondered if it might perhaps help to summarise the problems before we get our virtual scalpels out, so here goes with my assessment!

Velocity and cadence and stride length seem surprisingly reasonable although it's difficult to be sure without knowing body height or limb length - using the nomogram on p.136 of Inman, they seem to be OK. The stance phase is increased on the right, with a shorter step length on that side.

The left foot has a marked equinus deformity, with forefoot inital contact and flat moment curve and clonus, whilst the right is a rather flat-footed, toe-in, lateral border contact, also with clonus. The clonus in both ankles is confirmed by the EMG.

There are flexion deformities of both knees, slightly worse on the left, with inappropriate/early extensor (rectus) activity in terminal stance on that side (confirmed by EMG). Conversely, the right side shows increased flexor moment, which doesn't seem to be well confrimed by hamstring EMG - perhaps adductors?

The left hip is so internally rotated that the curve has actually disappeared off the top of the M.A.C. plot! It is 60 deg. anteverted on clinical examination, so maybe some of this is artefact (comments?). Despite this, toeing-in looks worse on the right, so this must be due to tibial torsion. In the sagittal plane there is a large compensatory H1 power on the right. Pelvis drops (Trendelenberg) and tilts anteriorly during left swing, implying weak right hip abductors (confirmed by moment curves), with lateral trunk flexion and a lateral arm thrust on that side. Despite this, foot clearance looks greater on the left. The trunk also hyperextends at right toe-off - I'm not sure why.

Putting it all together, the main problems are:

Here's what I would suggest:

I realise that's quite a shopping list, but this is quite a complicated case. What do others think?

Chris -- Dr. Chris Kirtley (Kwok Kei Chi) MD PhD Assistant Professor Department of Rehabilitation Sciences The Hong Kong Polytechnic University

I would like to use the OGA form but am a bit puzzled about the right/left issue...can someone please explain? I would like to do it before I look at the gait analysis data.

Also, could someone (Chris?) please explain the notable omission on hamstrings and psoas length and tell me what the heck a 60 degree "extension defecit" is at the ankle??

Looking forward to moving forward from here!

Jenni "Technology Unit (Anne Mackay SP, Rosemary McCormack OT, Jenni Dabelstein PT)" <rosemcc@gil.com.au>

I know what you mean about the form. It's a prototype, and this is the sort of feedback which will help improve the design. I guess we need separate sections for left and right. For now, just try to answer as best you can!

The extension deficit is the amount of knee flexion when it is extended passively to its limit by the examiner, with the hip at 90 deg. to put tension on the hamstrings - it's a test for hamstrings contracture.

Looking at the knee joint moment, there seems to be tight hamstrings on both sides, but the left is masked by an overactive rectus. I confess I missed that until you reminded me, so maybe he could benefit from a hamstrings release on the left, too.

Chris -- Dr. Chris Kirtley (Kwok Kei Chi) MD PhD Assistant Professor Department of Rehabilitation Sciences The Hong Kong Polytechnic University

Just wondering which review articles or research papers you would choose to read regarding treatment of gait disturbance in CP. I have, in my brief review, found no scientifically sound studies. The longitudinal follow-up studies have not supported any particular therapy and the rhizotomy stuff again appears to have quite differing results. Botox has very little evidence other than anecdotal.

You may wish to put this to the list to stimulate discussion. I mention this because it is one thing to acknowledge there are huge flaws in gait analysis but it is an even bigger step to use it as a method of deducing what surgery is required.

Regards,

Matt

Matt D Melbourne Foot Clinic 29 Leopold Crescent, Mont Albert, VIC, Australia 3127 Phone:61-3-9890 2212 FAX:61-3-9888 4978 Email:equus@ozemail.com.au WWW: http://www.ozemail.com.au/~equus

One way around the flaws in measurement technology is to make decisions based on confirmatory evidence from e.g. clinical exam, video, kinematics, kinetics and dynamic EMG. I hope I've demonstrated that in this case. And, of course, in medicine tests should always be used in the perspective of the full clinical picture. The purpose of Case of the Week is to provide a platform for developing the interpretation skills necessary for understanding a gait analysis.

And I think it's worth pointing out that all diagnostic methodologies, be they history-taking, the naked eye, clinical examination, even clincal experience etc. have their flaws, biases & limitations.

I agree that there is a lack of scientific studies - but they're starting to trickle through. Certainly, the rhizotomy literature is somewhat contradictory - perhaps that's why I put a ? mark before that suggestion!

Anbody any suggestions on review articles?

Chris -- Dr. Chris Kirtley (Kwok Kei Chi) MD PhD Assistant Professor Department of Rehabilitation Sciences The Hong Kong Polytechnic University

My colleagues and I in Cape Town have been invited to review the literature on rhizotomy for Gait & Posture -- the paper should be out sometime next year. In the meantime we have a paper with ten-year follow up data that is in review at the Journal of Neurosurgery. It was presented at the recent ISB meeting in Tokyo.

Kit Vaughan

Before jumping to rhizotomies, I would try some soft tissue mobilization techniques to see if the tone becomes more controllable as the tissue has greater mobility, and use therapeutic activities to strengthen the weak abductors and other muscles. I haven't seen this work in pediatrics first hand, but I have seen it work in adults.

Melanie Weller MPT

I finally got time to sit down and look at this case. A very "typical" spastic di...here's what I thought:

OGA The child looks unstable - there is a lot of excessive movement and looks like a lot of energy being expended. I wonder what the gait history is...is the gait starting to deteriorate? Asymmetry is immediately obvious, with the left arm held in "high guard" while the right swings in an exaggerated pattern.

The left foot demonstrates a toe-toe pattern with disruption of all 3 rockers and poor swing clearance. The right foot looks more like a toe-toe to foot-flat kind of pattern - no 1st rocker, possible inversion of second, early 3rd, swing clearance looks OK. The foot progression angle is internal both sides, more on the right, but the left foot looks like it's breaking at midfoot region. Both knee are too flexed at initial contact, but the right then extends rapidly...looks like a PF/KE couple and looks like pre-swing knee flexion is a bit diminished. The left knee stays flexed thoughout stance. There is a lack of hip extension in stance both sides and both look medially rotated...looks like a bony as well as motion issue. No real adduction..looks like flexion/rotation issues. The pelvis is too anteriorly tilted and increased motion evident in sagittal and frontal views. The lumbar spine is lordotic and the trunk sawy to the right in stance is marked..perhaps to help clear that left foot??

Clinical Exam A bit sketchy but confirms the clinical impression of increased anteversion/torsion - worse on the left according to exam. No info on psoas length...we need that. Adductors aren't too tight. Hams are borderline tight...worse on the left but only just into hack and slash range. ??true myostatic contracture or dynamic issues?? Positive Ely's...big news! I mistrust the "internal tibial torsion" on the left and would tend to suspect an unstable knee..too muh play to get a good measure. Increased spasticity at both ankles...probably some dynamic as well as myostatic contractures, but we don't have dorsiflexion range...need that!! I also want some foot measurements on the right foot...how unstable is it??

Time-Distance Not too awful. A bit increased cadence and decreased step/stride but a fair velocity. The left stance is shorter, as is the left step length, but asymmetries aren't too wild. Functional kid.

K&K The trunk sway we saw is confirmed. Double bump APT and the left pelvis drops way down in swing (makes sense...the right side looks more affected...weaker abductors??). Increased transverse pelvic motion to compensate for the hip extension defecits. Lack of hip extension both sides in stance, and the right looks a little stiff, too. The moments and powers show some timing problems and wasted power generation, but the magnitudes of moments and powers are not too bad...good sign. There is indeed no adduction of any significance (the left actually abducts a little, probably to compensate for the pelvis dropping) but medial rotation is huge on the left. The right rotation graph looks OK. I interpret that as increased motion on the left and probable increased anteversion/torsion (which the motion system doesn't measure) to accountfor the rest of the medial rotation we see clinically on both sides.

The knees are both too flexed at terminal swing/initial contact, then the right extends rapidly, although not to normal range. The left stays flexed thru stance. There is delayed and diminished peak knee flexion in swing bilaterally and both knees have decreased dynamic range overall. The left ankle is wildly plantar flexed through the cycle, with very decreased dynamic range...no real power generation as no real motion. The right ankle shows sharp inversion of second rocker corresponding with the rapid knee extension on that side and kinetics confirm the PF/KE couple. Good dynamic range of the right foot, but I wonder if the foot is breaking...the motion model isn't good at picking that up. I wonder if the dorsiflexion is happenning at midfoot rather than talocrural (probably is). Typical increased A1,A2 and decreased A3 on power graphs on the right.

EMG Confirms out-of-phase RF activity in swing bilaterally. Hams are on at stance-swing transitions..probably being overused as stabilisers. Gastroc/soleus normal peaks are very diminished indeed and increased gastrocs at initial contact is probably just a stretch reflex. The absence of lots of EMG activity in gastrocsoleus is starting to make those plantar flexion contractures look fixed.

Treatment Ideas I think, withou question, that this child should have intertrochanteric derotation osteotomies of both femurs. The increased medial femoral torsion come anteversion is a major functional and biomechanical issue. This child is a long-term, functional walker and this is the ideal time. Fix this!

I would also be open to a hip flexor release at the pelvic brim if clinical exam showed any significant shortening.

The hamstrings on the right I would fight not to touch right now: the rapid extension in stance is a big red flag and they're not really in operative range. The increased rotation stuff at the left hip could be influenced by hams and left is worse on exam....maybe a judicious recession of medial hams only. But, I'm aware that there's increased hams activity at transition from stance to swing...the child is probably using hams as stabilisers and we don't want to weaken them too much.

The left is the stiffer knee, too, so I would vote for rectus transfer with any hamstring release on that side. The issues on the right are not enough to indicate rectus transfer alone.

I think the child will need bilateral gastrocsoleus recessions...all the signs point to fixed plantar flexion contractures. Hopefully, enough range can be gained through a recession on the left without having to resort to a tendon lengthening procedure.

I think the right foot is unstable and breaking at the midfoot, so I would want to look more closely here. I am thinking along the lines of a lateral column lengthening or calcaneal osteotomy (all extra-articular, please!) to put the foot in a better weight-bearing position. Foot pain is waiting for this child if we don't get serious about protecting it.

The child should have good long-term PT arranged before any knives are drawn...outcomes won't be optimal without it. My preference for orthotic managment would be AFO's with limited, resisted dorsiflexion and some available but resisted plantar flexion. Probably a leaf-spring type design a la Cascade. No free hinges please! But locking up the ankle for too long will compromise strength too much...strength is vital to normalising gait.

What an epistle!! Sorry. This is my area!! Any comments from the mob out there???

Jenni

Jenni Dabelstein, Physiotherapist Technology Unit Queensland Spastic Welfare League 354 Bilsen Road, Geebung 4034 AUSTRALIA ph: 61 7 3874 2050 fax: 61 7 3874 2051

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