Stavros Alevrogiannis presentation in European Knee Associates (EKA) Closed meeting in Istanbul, Nov 27-28, 2015.

2. RECONSTRUCTION
OF
EXTENSOR MECHANISM
IN TKA
ST. A. ALEVROGIANNIS, MD, MSc (Orth.),PhD
SENIOR CONSULTANT IN ORTHOPAEDICS
MEDICAL DIRECTOR OF ORTHOPAEDIC CLINIC
IASO GENERAL HOSPITAL/ATHENS/GREECE
CLOSED MEETING- ISTANBUL , NOV. 27-28, 2015

3. Conflict of interest disclosure form
□ I have no potential conflict of interest to report
□ I have the following potential conflict(s) to report:
Type of affiliation / financial interest Name of commercial company
Receipt of grants/research supports:
Receipt of honoraria or consultation fees:
Participants in a company sponsored
speaker’s bureau
Stock shareholder:
Spouse/partner:
Other support:

4. EXTENSOR MECHANISM COMPLICATIONS IN TKA
Prevalence of 1-12%
Parker DA, Dunbar MJ, Rorabeck CH. J Am Acad Orthop Surg.2003 Jul-Aug;11(4):238-47.
Majority of them occur postop.
Surgeon must be aware intraop., postop. and for patient-related
factors
Most common seen:
1. Patellar tendon disruption
2. Quadriceps tendon rupture
3. Patellar crepitus & soft tissue impingement
4. Periprosthetic patellar fracture
5. Patellofemoral instability
6. Patellar osteonecrosis

5. RISK FACTORS
•SURGICAL TECHNIQUE- MEDIAL ARTHROTOMY
•POOR PATELLAR ALIGNMENT
•PATELLAR OVER-RESECTION
•PRIOR SURGICAL PROCEDURES
•PATELLA BAJA
•OBESITY
•INFLAMMATORY ARTHRITIS
•DIABETES MELLITUS
•CORTICOSTEROID USE
•HYPERTHYROIDISM
•TYPE OF PROSTHETIC MATERIALS (FEMORAL
THROCHLEA)
•MALALIGNMENT OF PROSTHETIC MATERIALS

6. RECONSTRUCTION OPTIONS
•ALWAYS SURGICAL?
•VARIETY OF SURGICAL OPTIONS !
•THE SELECTED OPTION IS BASED ON:
1. The quality of the host tissue
2. Level of disruption (quads, patella, p.tendon)
3. Degree of functional loss ( partial or full tear)
4. Acute versus chronic nature
5. The availability of host autograft and
allograft to assist with the repair
6. Patient’s functional demands

7. TREATMENT OPTIONS FOR SURGICAL REPAIR INCLUDE:
•Direct primary repair by suturing, stapling or
wiring the tendon to the tubercle
•Primary repair with biologic or synthetic graft
augmentation (e.g gracilis, free fascia lata,
plantaris, semitendinosus,or gastrocnemius
rotational muscle flap )
•Allograft tissue augmentation
•Salvage techniques ( patellotibial fusion, knee
arthrodesis, or above knee amputation) if surgical
repair fails or reconstruction is impossible.

8. PATELLAR TENDON RUPTURE (≤ 1%) TREATMENT OPTIONS
•Depend on aquity and location of the injury, quality of remaining tissue, patient’s age
and daily demands.
•Bracing for those with low daily activities, those with a partial tendon tear and for those
that are poor surgical candidates
•Arthrodesis in a case of periprosthetic infection
•Direct repair if rupture occurs intraoperatively or in the immediate postoperative period
( staples, drill holes, suture anchors)
Parker DA, Rorabeck CH. J.Am. Acad. Orthop.Surg. 2003, Jul-Aug 11(4):236-47
•Augmentation should always be used in chronic ruptures.
•Augmentation technique, in the presence of poor tissue quality, should be used
Schoderbeck et al. Clin. Orthop. Relat. Res. 2006 May;446:176-85
•Primary repair without augmentation results in high rates of deep infection, tendon re-
rupture and extensor lag
Browne JA,Hanssen J.Bone Joint Surg.Am. 2011 Jun 15;93(12):1137-43
•Augmentation options :
1. Hamstring allograft
2. Fresh frozen or freeze-dried Achilles tendon bone-block
3. Extensor mechanism allograft
4. Synthetic graft (Marlex mesh or knitted monofilment polypropylene
Browne JA,Hanssen J.Bone Joint Surg.Am. 2011 Jun 15;93(12):1137-43

9. TREATMENT ALGORITHM
THE JOURNAL OF BONE & JOINT SURGERY. JBJS,ORG, VOLUME 96A, NUMBER 6, MARTCH 19 ,2014

10. QUADRICEPS TENDON RUPTURE (≤ 0,1%) TREATMENT OPTIONS
•SPECIFIC RISK FACTORS : SYSTEMIC DISORDERS, EXCESSIVE PATELLAR RESECTION
AND A PRIOR QUAD-SNIP OR V-Y TURNDOWN
Parker DA, Rorabeck CH. J.Am. Acad. Orthop.Surg. 2003, Jul-Aug 11(4):236-47
•CONSERVATIVE TREATMENT WITH KNEE IMMOBILIZATION IN FULL EXTENSION
FOR PARTIAL TEARS
•SURGICAL DIRECT REPAIR FOR COMPLETE TEARS HAS LIMITED SUCCESS !
(33-36% RE-RUPTURE)
(33-100% OVERALL COMPLICATIONS-INCLUDING INFECTION)
Lynch AF, Rorabeck CH, Bourne RB. J.Arthroplasty. 1987;2:135-40
Dobbs RE, et al. JBJS Am. 2005 Jan;87:37-45
• AUGMENTATION IS STRONGLY RECCOMENDED IN ALL CASES OF COMPLETE
RUPTURE
Dobbs RE, et al. JBJS Am. 2005 Jan;87:37-45
•AUGMENTATION OPTIONS:
1. SEMITENDINOSUS OR GRACILIS AUTOGRAFT
2. SYNTHETIC GRAFTS
3. ACHILLES TENDON OR COMPLETE EXTENSOR MECHANISM ALLOGRAFTS

11. SYNTHETIC GRAFT FOR AUGMENTATION
•Dacron, Gore-tex polypropylene & Leeds-Keio artificial ligament
•Concerns with synthetic implants include an increased risk of infection and the
risk of poor tissue holding strength in pts who have undergone TKA revisions
Aracil J., J.Arthroplasty, 1999;14:204-208
• Post-op ROM 0-1100 in a patient with a quad’s rupture, which was repaired
with tenoplasty augmented with Dacron
Ecker ML, JBJS Am 1979; 61: 884-886
• post-op ROM 146,40 using the Leeds-Keio ligament in either patellar (6 pts) or
quad’s ( 5 pts) rupture. With F-U 3.5y.only 4 pts had extensor lag  100.
Fernandez-Bailo N., J.Arthroplasty; 1993;8:331-334
•post-op ROM from -4.60 of extension to 980 of flexion using the Leeds-Keio
ligament in 5 pts with a minimum F-U of 38m.
Aracil J., J.Arthroplasty, 1999;14:204-208

12. SEMITENDINOSUS AUTOGRAFT
• Stronger repair than fascial strips and free grafts for
reconstruction of the patellar tendon
Ecker ML., et al JBJS Am 1979;61:884-886
Gustilo RB., et al Total Knee Arthroplasty . Proceedings of the Knee
Society, 1985-86, Aspen 41-47, 1987
• When tension is applied to the semitendinosus tendon it is
important that the Insall- Salvati ratio is in a normal position as
tension is applied to the free end of the tendon and checked in
900 of flexion to avoid undue stress on the graft . The Insall-
Salvati ratio has to be calculated to ensure that the patella is held
in right position.
Cadambi A., et al. JBJS Am.1992;74:974-979
Insall J.,Salvati E. Radiology 1971;101:101-104
• Varied outcomes !!!
Rand JA et al, Clin. Orthop.Relat.Res 1989;144: 233-238
Jaureguito JW, et al, JBJS Am 1997;79:866-873

13. AUTOLOGOUS (GASTROCNEMIOUS ROTATIONAL FLAP) GRAFT
•Augment repair of the extensor mechanism in pts with exposed prosthesis,
infection, loss of extensor mechanism and a history of previous patellectomy
Jaureguito JW, et al, JBJS Am 1997;79:866-873
•This rotational flap provides a vascularized muscle bed that promotes healing
of the reconstructed extensor mechanism and does not rely on bone quality of
the proximal tibia or patella and gives adequate soft tissue envelope for the
components making late failure unlikely
Malawer MM., et al Clin Orthop. Rel.Res. 1989;239: 231-248
•Average ROM of 3-930 and average extensor lag of 13,50 .
Busfield BT, et al Clin. Orthop. Rel. Res. 2004;428:190-197
•Average ROM from 700 pre-op to 1000 post-op , average extensor lag of 240
and improvement walking status
Jaureguito JW, et al, JBJS Am 1997;79:866-873

14. USE OF ALLOGRAFTS
• CONCERNS FOR
1. Immune reaction (diminished by deep freezing)
2. Disease transmission (extremely rare)
3. Graft strength- failure risk
4. freeze-dried grafts are weaker than fresh frozen and have a greater risk of
generating a host immune response.
Buck BE., et al. Clin. Orthop.Relat.Res. 1989;240:129-136
Parker DA., et al. J.Amer.Academy of Ortho. Surg.2003;11:238-247
Zanotti RM., et al. J.Arthroplasty. 1995;10:271-274
• Advantages:
1. Unlimited supply
2. Variety of tissue types
3. Absence of donor site morbidity
• Improved ambulatory ability, no loss of flexion and improved extensor lag
( hinged knee brace for 6w with limited motion up to 600 for the first
6w.gentle active exercises to 900 by the end of 12w and PWB during
bracing).
Emerson RH., et al Clin. Orthop.Relat.Res. 1990;260:154-161
Emerson RH., et al Clin. Orthop.Relat.Res. 1994;303:79-85

15. TREATMENT ALGORITHM FOR QUAD’S RUPTURE
THE JOURNAL OF BONE & JOINT SURGERY. JBJS,ORG, VOLUME 96A, NUMBER 6, MARTCH 19 ,2014

16. PERIPROSTHETIC PATELLAR FRACTURE (0,68-5,2%)
•RISK FACTORS :
1. Excessive patellar resection
2. Patellar implant with large central plug or metal backed cementless component
3. BMI  30Kg/m2
4. Osteoporosis
5. Combined femoral & tibial component malrotation
6. Overall component malalignment in coronal plane
• TYPE I: stable implant + intact extensor mechanism
TYPE II: stable implant + extensor mechanism disruption
TYPE IIIa : loose implant + good bone stock
TYPE IIIb : loose implant + poor bone stock
• KEY TREATMENT CONSIDERATIONS :
1. Location & pattern of the fracture
2. Integrity of extensor mechanism
3. Implant stability
4. Quality of remaining bone stock
• COMPLICATIONS ( even after anatomic fracture reduction & reconstitution of extensor
mechanism)
1. Nonunion
2. Ipsilateral tendon rupture
3. Secondary fatigue fracture
4. infection

17. SURGICAL TREATMENT OF PERIPROSTHETIC PATELLAR FRACTURES
• Excellent results with non-operative management in 37 pts with a well-fixed
implant and an intact extensor mechanism following a periprosthetic patellar
fracture with only one late failure
In 12 pts with an extensor mechanism disruption surgical repair of either the
extensor mechanism or the fracture resulted in a 42% reoperation rate, 50%
complication rate and 58% prevalence of extensor lag post.op
Surgical management of 12 pts with a loose patellar component resulted in a
reoperation rate of 20% and an overall complication rate of 45%.
Ortiguera CJ, Berry DJ. JBJS Am. 2002 Apr;84(4): 532-40
• Similar clinical results
Bourne RB. Orthop.Clin.North. Am. 1999 Apr;30(2): 287-91
Goldberg VM, et al. Clin. Orthop. Relat.Res. 1988 Nov;236: 115-22

18. TREATMENT ALGORITHM
(Parker DA, Dunbar MJ, Rorabeck CH. J.Am.Acad.Orthop.Surg.2003 Jul-Aug;11{4}:238-247)

19. Take Home Message Page
• Complications involving
the knee extensor
mechanism can be difficult
to manage
• Patients should be
counceled regarding the
severity of their problem
and their expectations
should be managed
appropriately