Dott. Daniele Priano — Ortopedia Pediatrica · ortopediaevolutiva.com

Tibial Spine (Eminence) Fracture: reduction and fixation with bioabsorbable pins

Name: Tibial Spine (Eminence) Fracture: reduction and fixation with bioabsorbable pins
Creator: Dott. Daniele Priano

Five-phase protocol after reduction and fixation of a tibial eminence fracture with bioabsorbable pins (Smart Nails), screws or suture: the paediatric equivalent of an ACL injury, except that here bone heals, not ligament.

Immobilisation in extension 30 days · Non-weight bearing 30 days · Full weight bearing 6-8 weeks · Running 3-4 months · Pivoting sport 6-9 months

This protocol is part of the post-operative pathway and must be adapted to the surgeon’s instructions and to the individual clinical response.

These documents are protocol templates for information and education only: they do not replace the rehabilitation prescription for the individual case. Timing, loading and progressions must always be adapted to the patient, the lesion pattern, the surgical technique used and the clinical course, in collaboration between orthopaedic surgeon, physiotherapist and, where appropriate, physiatrist. Progression is driven by objective criteria, not by the calendar alone.

At a glance

Brace: Brace locked in extension or a cast for 30 days, day and night, unless the surgeon indicates otherwise.
Weight bearing: Non-weight bearing (foot not placed on the ground) with crutches for the first 30 days; progressive loading only after the clinical and radiographic review, with full weight bearing usually between weeks 6 and 8.
ROM: Knee kept in extension during the first month; flexion is started and progressed after the one-month review, usually 0-60° within a few days, 0-90° by week 6 and full ROM between weeks 8 and 10.
Main risk: Arthrofibrosis (loss of extension or flexion). If flexion is not progressing or full extension is missing at the second-month review, immediate clinical reassessment is required, not watchful waiting.
Bone healing: Radiographic check at about 4 weeks; union generally over a few weeks, confirmed clinically and radiographically.
Running: Usually from months 3-4, with full ROM, a dry knee and quadriceps ≥80%.
Return to sport: Non-contact sport at 4-6 months; pivoting and contact sport at 6-9 months with functional tests passed and clinical stability.

Days 0-30Fixation protected: extension and non-weight bearing
4 weeksRadiographic check and start of flexion
6 weeks90° flexion, progressive loading
Weeks 6-8Full weight bearing, brace discontinued
Months 2-4Strength ≥80%, stable full ROM
Months 4-6Running, plyometrics, agility
Months 6-9Return to pivoting sport

In children and adolescents with open physes, the bone of the intercondylar eminence is weaker than the anterior cruciate ligament attached to it. A twisting injury that would tear the ligament in an adult therefore avulses a bony fragment from the tibial plateau instead: this is a tibial spine (eminence) fracture. The ACL generally remains attached to the fragment, but it may have stretched at the time of injury and associated meniscal or chondral lesions can coexist.

The biological advantage is real: bony union generally occurs over a few weeks and is confirmed clinically and radiographically, faster than the integration of a reconstructed graft. The main risk is therefore not failure of healing but stiffness: arthrofibrosis (loss of extension or flexion from scar tissue) is the most frequent complication after this operation. This protocol nevertheless applies strict early protection — brace locked in extension or a cast and non-weight bearing for 30 days, as indicated by the surgeon — because maintaining the reduction comes first. Recovery of motion is not left to chance: it is planned and checked at the clinical and radiographic review at the end of the first month, and from then on it becomes the priority objective.

The Meyers and McKeever classification describes fragment displacement: type I (undisplaced, usually treated in a cast), type II (hinged posteriorly), type III (completely displaced) and type IV (comminuted or rotated). Irreducible type II, type III and type IV injuries are generally treated arthroscopically.

Fixation may use bioabsorbable pins such as Smart Nails (polylactic acid polymer), metal screws, or high-strength suture anchored to the tibia. The choice depends on fragment characteristics (size, comminution, cartilaginous component), age and remaining growth, technique and surgeon experience. Bioabsorbable pins avoid a second operation for removal and can be placed avoiding problematic transit through the proximal tibial growth plate. In all cases rehabilitation progression remains surgeon-guided and is never forced.

This protocol mainly describes the pathway used after fixation with bioabsorbable pins: with other fixation techniques the instructions on bracing, weight bearing and motion recovery may differ, and the operating surgeon’s instructions prevail.

One point to explain to families: even after complete bony healing, mild anterior laxity may remain — measurable but often asymptomatic — because the ligament had already stretched at the time of injury. What matters clinically is functional stability, i.e. the absence of giving-way episodes during sport.

What the surgery does

Loading timeline

The choice of fixation depends on fragment size and quality, patient age and proximity of the growth plate. It mainly changes how cautiously flexion is progressed in the first weeks.

	Bioabsorbable pins (Smart Nails)	Metal screws or high-strength suture
Material	Bioabsorbable polymer (polylactic acid) that degrades progressively over months.	Titanium or steel screws, or high-strength fibre suture anchored to the tibia.
Second operation	Not required: the pin resorbs.	Screws may need removal, especially if prominent or symptomatic.
Relationship with the physis	Can be placed sparing the growth plate; ideal in children with very active physes.	Suture is physeal-sparing; screws require careful placement to avoid crossing the physis.
Mechanical strength	Good but lower than a metal screw: flexion progression is more cautious in the first weeks.	High with screws; suture provides excellent hold even in comminuted fragments.
Comminuted fragment	Less suitable when the fragment is in several small pieces.	Suture is often the best option because it gathers the fragments.
Rehabilitation	Same goals, with slightly more gradual flexion progression after the first protected month.	Usually allows slightly faster flexion progression, always on the surgeon’s instruction.

In every case the aim is the same: protect the fixation during the first month and, after the radiographic review, regain full extension and flexion promptly to prevent arthrofibrosis.

Step by step

Each phase lists the goals, what to do and the exercises for that exact moment: do not anticipate them. Dosage is indicative and must be adapted by your physiotherapist.

Before surgery — Preparation for surgery (educational)

In the hours or days before surgery: this is a traumatic lesion that often needs early treatment.

When it applies

•No prehabilitation programme applies: the tibial spine fragment must not be stressed.
•Preparation is purely educational and organisational, addressed to the young patient and the family.

Goals before surgery

•Understand the immobilisation and knee position planned after surgery.
•Understand initial off-loading and crutch use.
•Know the post-operative goals of the first weeks (extension, muscle activation, gradual flexion recovery).
•Know which warning signs to report immediately (worsening pain, rapid swelling, changes in sensation or movement, change in colour or temperature of the foot).

Activities

•Crutch training with the prescribed off-loading, avoiding any movement that loads or mobilises the injured knee.
•Explanation of the brace/immobilisation and of transfers (bed, chair, car, bathroom).
•No exercises of the injured knee before surgery.

Preoperative exercises

Crutch and weight-bearing training

•Try the crutches before surgery, with correct height and the weight-bearing status set by the surgeon.
•Practise on level ground, stairs and the entrance to your home, with someone assisting.
•Also practise sitting, standing and moving in the bathroom while respecting the planned loading restrictions.

Dosage: At least one training session before admission; repeat until the technique is safe.

Readiness criteria for surgery

☐The young patient moves safely with crutches, without loading the limb.
☐Family informed about immobilisation, timing and post-operative goals.
☐Paperwork and home arrangements ready for admission.

When surgery must not be delayed

•Tibial spine avulsion is a traumatic lesion: treatment must not be postponed for rehabilitation reasons.
•Knee blocked short of extension by fragment interposition: timely treatment.

What to prepare at home and school

•Organise movement at home: clear pathways, remove rugs, keep useful items within reach.
•Prepare ice, a support for the heel, comfortable clothing and crutches already adjusted.
•Inform school or the sports club: plan the absence, temporary exemption and gradual return.
•Agree the first post-operative physiotherapy session in advance.

Phase 1 — Protecting the fixation in extension, non-weight bearing

Indicative timing: Days 0-30

The time window is indicative: progression depends on the criteria listed below, not on the calendar.

Goals

•Protect the fixation and maintain the reduction
•Maintain full extension
•Prevent quadriceps inhibition

What to do

•Brace locked in extension or a cast, day and night, for 30 days
•Non-weight bearing with crutches: the foot is not placed on the ground, unless the surgeon indicates otherwise
•Isometric quadriceps contractions and braced straight-leg raises several times a day
•Active ankle and hip mobilisation, patellar mobilisation if permitted and if the immobilisation allows it
•Cryotherapy and compression, limb elevated; dressings and wound care as instructed at discharge

Restrictions and precautions

•No weight bearing on the operated limb
•No knee flexion beyond what is expressly authorised
•No resisted hamstring work
•No twisting or activity on slippery ground

Exercises for this phase

1. Quadriceps isometric contraction (quad set)From day 1

•Lie on your back with the leg straight and a rolled towel under the ankle.
•Push the knee down by tightening the thigh, as if flattening the bed.
•The heel lifts slightly: that means you are reaching full extension.

Dosage: 10 contractions of 5 seconds, 4-6 times a day

2. Prone hang (passive extension)From day 1 — the most important exercise

•Lie face down on a bed with the operated leg over the edge from the knee down.
•Let the weight of the leg extend the knee: no pushing, just gravity.
•If needed, add a small ankle weight (0.5-1 kg) after the first week.

Dosage: 10 minutes, 3-4 times a day

3. Straight-leg raiseFrom day 1-2

•Lying on your back, first tighten the thigh until the knee locks straight.
•Lift the straight leg about 30 cm, hold 3 seconds and lower slowly.
•If the knee bends while lifting, the quadriceps is not ready yet: go back to quad sets.

Dosage: 3 sets of 10, twice a day

Ready for the next phase when

☐Healed wound
☐Good quadriceps control within the brace
☐Decreasing pain and effusion
☐Clinical and radiographic review at 4 weeks confirming the reduction is maintained

Note for the physiotherapist

In this first month the aim is not to gain degrees of flexion but to protect the fixation: useful work means isometric quadriceps recruitment and maintaining extension. Motion progression starts after the radiographic review and is agreed with the surgeon.