Introduction

• Fracture of Pars interarticularis (Narrow isthmus of bone that lies between the two articulating facets - one superior and and one inferior)
• Usually childhood fracture
• Usually in Lumber spine
• Common in sports that require episodes of Hyperextension, especially if combined with rotation. Eg; of common sports - Gymnastics, fast bowling (cricket), Tennis, rowing, dance, weightlifting, wrestling, pole vaulting and high jump and throwing activites
• Usually at opposite side of activity (that is; In right handed person, fracture is common seen in Left).

Clinical Features

• Unilateral low back pain, occasionally associated with somatic buttock pain
• Aggravated by movements involving hyperextension of lumber spine
• Occasionally asymptomatic

O/E

• Pain maybe reproduced by hyperextension with rotation of Lumber spine
• And on extension while standing on the affected leg.
• Associated hamstrings spasm with excessive lordosis may present
• Tender over fracture site

Diagnosis

• Xray - maybe normal (or) may showScotty dog appearance of a pars defect in Long stranding fracture
• If Xray Normal, SPECT scan to detect active stress fracture or stress reaction (Increase bone uptake)
• If SPECT positive - CT (reverse gantry) - to detect fracture line
• Alternatively - MRI can be used (not as sensitive as combined use of SPECT and CT)

Stages (by Radiology images)

• Early - Focal bone absorption or Hairline defect
• Progressive - Wide defect and small fragments
• Terminal - Sclerotic changes

Prognosis

• Early and half of progressive type achieved radiological healing
• Terminal cases - will not heal
• L4 fracture is better chance of healing than in L5

Management

• Initially - Rest and avoid aggravating movment (ie; lumber extension and rotatoin)
• There is no definitely time set period to rest. PAIN should be used as a guide
• Rehab program aims at painfree progressive exercises
• When there is no longer local tenderness and aggravating activity is none tender, gradually resume the aggravating activity over 4 - 6 weeks.

Other Management

• Specific exercise program training on Transverse abdominus and Multifundus (O'Sullivan et al's)
• Core stability exercises
• Assessment and modification of biomechanics and technique