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Compressive Osseointegration

Judd Cummings MD, FACSClinical Assistant Professor Department of Orthopedics

University of Arizona

Disclosures

None

Background

Anchoring large endoprosthetics to host bone is challenging

Current techniques include long stemmed cemented or uncemented prostheses

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Background

A major complication seen regardless of technique remains aseptic loosening

Post op 2 yrs 4 yrs 5 yrs

Wolff’s Law

Use it or loose it

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cm cm

C.W. 24 y/o female s/p OS 10 yrs priorrightrlrightrl

cm cm cm cm

Post - op

Aseptic LooseningCemented Stems

– 14% 776 pts (distal femur) at avg f/u 15 yrs.Jeys et al. JBJS. 2008;90(6): 1265-1271

– 35% 846 pts (knee, hip) at avg f/u 46 months. Unwin et al. JBJS Br. 1996;78(1):5-13

– 25% 17 pts (knee) at avg f/u 46 months. Kinkel et al. J Surg Onc. 2010 Feb 1; 101 (2): 166-169

– 38% 13 pts (distal femur) at avg f/u 96 months. Kawai et al. JBJS. 1998; 80: 636-647

– 23% 22 pediatric pts (distal femur) at avg f/u 156 months. Futani et al. JBJS 2006 Mar; 88 (3): 595-603

Uncemented Stems– 2% 47 pts (knee, hip, shoulder, intercalary) 12 month f/u.

Blunn et al. CORR. 2000 Mar; 372: 223-230– 9% 60 pts (knee) at avg f/u 46 months.

Kinkel et al. J Surg Onc. 2010 Feb 1; 101 (2): 166-169– 24% 50 pts (distal femur) at avg f/u 88 months.

Farfalli et al. CORR. 2009 Nov; 467 (11): 2792-2799– 41% 27 pts (distal femur) at avg f/u 96 months.

Kawai et al. JBJS. 1998; 80: 636-647

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ComPreSs®

FDA Cleared 510(k) – 2003– Femur (proximal, distal, intercalary)

– Humerus (proximal, distal)

Rigid fixation and compression to encourage osteointegration

Stress sharing of entire cortical structure

Seal out particulate debris from medullarycanal

ComPreSs® Technique

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Initial Compress® Experience

Bhangu et al, Int Orthop, 2006– 26 distal femur implants, avg f/u 2 yrs

– 1/26 implant related failures

– Equivalent implant survival to cemented stems

O’Donnell, CORR, 2009– 16 tibial implants, min f/u 2 yrs (2-10 yrs)

– 1/16 aseptic loosening

Healey et al, CORR, 2009– 41 distal femur implants, min f/u 3 mo (3m-7y)

– 1/41 implant related failures

Initial Compress® Experience

Pedtke et al, CORR 2012– 1/26 distal femur implants failed, avg f/u 6.2 yrs

– 83.5% vs 66.6% survivorship compared to cemented stems for aseptic loosening (p=0.22)

Monument et al, CORR 2015– 18 femoral implants, avg f/u 5 yrs

– 2/18 aseptic loosening

Goldman et al. CORR 2016– 75 distal femur implants, avg f/u 7 yrs

– 6/75 aseptic loosening

Compress® Versatility

Proximal / distal femur

Proximal / distal humerus

Expandable (growing implant)

Proximal tibia (not FDA cleared)

Short segment revisions

Intercalary segments

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S.F. 12 y/o female - OS

S.F. 12 months postop

S.F. 3 years postop

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A.R. 9 y/o female - Ewings

After 5 revisions over 7 yrs

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A.R. 3 mo post op

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J.L. 11 y/o female - OS

3 yrs post op

L.S. 16 y/o female - OS 3 yrs

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Expandable (invasive) prosthesis with Compress fixation

12 months postop

3 years postop

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Revision to Compress

RevisionAseptic loosening

12 months post op

9 y/o female with distal femoral OS

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Revision to Compress Fixation and Expandable Implant

4 months postop

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6 months postop

9 months postop

Stress Fracture

9 months

12 months postop

Healing

Lengthened

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15 months postop

Healed

More length

18 months

18 months postop

18 months

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S.S. 75 y/o female 3 yrs post op tx MVA

S.S. 4 mo post - op

Multi-Institutional Retrospective Analysis

A total of 104 patients with 121 CPS implants met our inclusion criteria– 99 patients were treated for oncologic

purposes

– 5 patients received the CPS device for non-oncologic applications

Average duration of follow-up was 51 months (range 13 - 120 months)

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Patient DemographicsGender: Male - 55 Female - 49

Average age: 29 yrs (range 7 – 69 yrs)

Average resection: 18 cm (range 10 – 31 cm)

Adjuvant Therapies: 74/104 pts

Post op regimen: all patients min 6 weeks NWB

Location and Diagnosis

Osteosarcoma – 65Chondrosarcoma – 13Ewings Sarcoma – 7MFH - 4Desmoplastic Fibroma – 3Malignant PhosphaturicMesencymal Tumor – 2Giant Cell Tumor – 1Lymphoma – 1Secondary Bone Sarcoma – 1Rhabdomyosarcoma – 1Metastatic Carcinoma – 1Irradiated bone fracture – 1 Non Oncologic Reconstruction – 4

4

79

21

4

79

Results

12 of the 121 implanted Compress®

devices demonstrated radiographic and/or clinical evidence mechanical failure

10% failure rate

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Results

Overall, 23 devices were revised or removed– 12 for issues unrelated to Compress® implant

Infection - 7

Peri-prosthetic fx - 1

Arthrofibrosis - 1

Soft tissue local recurrence – 1

Combined – 2

– 11 for Compress® device failure

Complications

11 patients revised due to Compress implant failure

8 pts successful revision with same or new CPS

2 pts revised to cemented stem

1 pt treated with amp

Implant Failures (12)

Time to failure: 1 – 54 months (avg 12 mo)Gender: Male - 8 Female – 4 (ratio 2:1)

Male - 55 Female – 49 (ratio ~ 1:1)Average age: 26 yrs (range 9 – 66 yrs)

29 yrs (range 7 – 69 yrs)Average resection: 16 cm (range 8 – 20 cm)

18 cm (range 10 – 31 cm)Adjuvant Therapies: 10/12 pts (83%)

74/104 pts (71%)

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Implant Failures (12)

Osteosarcoma – 8

Chondrosarcoma – 1

Malignant PhosphaturicMesencymal Tumor – 1

Giant Cell Tumor – 1

Irradiated bone fx – 1

11

1

Modes of Failure

Rotational loosening (5)

Subsidence (7)

Other mechanisms reported elsewhere– Traction bar breakage

– CPS adaptor breakage

– Translational instability

13 year old male with Osteosarcoma of distal femur

Post op 6 months 12 months

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14 yr old osteosarcoma right distal femur

14 mo post op revision

Other reported failure mechanisms

Gap between centering sleeve and endosteum

A.D.18 y/o tx for OS - 2011

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Failure 2 yrs post - op

Revision

32 mo post - op

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N.G. 27 y/o female, 15 yrs s/p Ewings: Multiple allograft revisions

3 mo post - op

6 mo post - op

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Post – op revision

8 mo post – op revision

S.S.

2 mo

Post op

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4 mo

6 mo

Post oprevision

2 wks 4 wks

Avoiding Complication

Patient selection

Must have biology to be successful– Host factors

Infection

Nutrtion

Age

– Extrinsic factorsCHEMO / XRT

Ability to comply with post op regimen

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Avoiding Complications

Avoid overloading thin cortex

Appropriate post-op regimen

Anti-rotational pins

Surgical Principles

• Level of bone resection / osteotomy– Adequacy of cortical bone

Infection

Radiation

Cement

Stress shielding

– Must have biology to be successful

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Properrevisionlevel

Old stemcavity

Surgical Principles

• Marking orientation (anterior reference line) prior to osteotomy

• Maintaining a good soft tissue sleeve including periosteum (must preserve biology)

Weight Bearing

Initial postop period: Touch-down weight bearing 6 weeks– Host biology

Infection

Radiation

Prior surgery

– Chemotherapy

Advance slowly thereafter based on radiographic evidence of bone formation

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Activity

Allow active ROM exercises immediately

Passive and active assist ROM when soft tissue envelope is stable

No resistive exercises (muscle strengthening) for minimum of 3 months

No rotational movement (torque) for minimum of 6 months

Take Home Points…..

Short-term results for the Compress®

implant are encouragingCompress® is a reliable and safe alternative to conventional stemmed endoprosthesesParticularly useful for– Pediatric patients – Short segment revisions

Appropriate indications, and surgical technique will influence outcomes

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1 Double reamer trimmed.mpg_WMV V9.wmv

2 facing reamer (trimmed)_WMV V9.wmv

3 anchor plug insertion_WMV V9.wmv

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3.1 Pin insertion_WMV V9.wmv

5 Second facing reamer_WMV V9.wmv

6 Compress implantation_WMV V9.wmv

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7 Final implant insertion_WMV V9.wmv