TKA in valgus knee is challenging procedure seen in up to 10% of cases undergoing TKA. The procedure involves meticulous pre operative planning and intra operative soft tissue release along with modifications in bone cuts for proper implant placement and long term results
1. TKA in valgus knee
Presenter : Dr Ajay
Moderator : Dr Avinash
Balaji institute of research and rehabilitation for the disabled
Tirupathi.
2. • Valgus knee deformity is a challenge in total knee arthroplasty (TKA)
and it is observed in nearly 10 % of patients undergoing TKA.
• Defined as a valgus angle equal to or greater than 10°
• The valgus deformity is sustained by anatomical variations divided
into bone remodelling and soft tissue contraction/elongation
3. Causes
• Congenital
• persistence of genu valgum from childhood secondary to metabolic disorders,
such as rickets and renal osteodystrophy.
• secondary to osteoarthrosis,
• Rheumatoid arthritis
• post-traumatic arthritis
• over-correction consequent to a valgus osteotomy
4. Pathophysiology
• In the valgus knee the lateral soft tissue structures, including the LCL, ITB,
and lateral capsule, contract, while the medial soft tissues become
stretched.
• The lateral femoral condyle has been shown to be frequently dysplastic in
the valgus deformity. Most of the bony deficit occurs on the femoral side.
5. • In long-standing deformity, lateral contracture and medial lengthening
become permanent . This combination of pathologies may result in a
medial thrust or scissoring during gait.
• valgus contractures may be associated with a flexion contracture or
occasionally recurvatum.
• A fixed external rotation deformity often accompanies valgus instability,
particularly in patients with inflammatory arthritis.
6. • The valgus deformity is sustained by anatomical variations divided into
bone tissue remodelling and soft tissue contraction/elongation.
Bone and cartilage variations consist of
• lateral compartment cartilage erosion,
• lateral condylar hypoplasia
• metaphyseal femur and tibial plateau remodelling
7. Soft tissue variations are represented by tightening of lateral structures:
• lateral collateral ligament (LCL),
• posterolateral capsule (PLC),
• popliteus tendon (POP),
• hamstring tendons,
• lateral head of the gastrocnemius (LHG)
• iliotibial band (ITB).
• Some authors also described a posterior cruciate ligament (PCL) alteration in valgus
knees, but in the literature its influence in maintaining the deformity is not universally
recognised
8. Knee evaluation
• A crucial point is to assess if valgus deformity is fixed or still reducible.
• If a fixed deformity is present, the lateral structures are tight and
medial ligaments are lax.
• If the deformity is reducible, soft tissue release will be less invasive, and
a standard unconstrained prosthesis could be sufficient
9.
10. External rotation deformity of femur
due to metaphyseal remodelling.
CT scan can be accurate in evaluating
rotational deformity
11.
12.
13. pre-operative radiographs
These are useful for planning and bone stock evaluation.
• Attention should be focused on
• lateral distal femoral hypoplasia,
• posterior femoral condyle erosion and
• metaphyseal remodelling both of the femur and tibia, which can lead
to malalignment or malrotation of the femoral component
14.
15.
16. • Trochlear hypoplasia can lead to patellar maltracking and subluxation hence sky
line view of patella is a must in pre operative evaluation of valgus knee
17. • The MCL was considered
sufficient when joint
deformity did not increase .
• attenuated when the
deformity increased but
with a clear mechanical
stop.
• Incompetent when the
deformity increased like a
hinge, without a clear stop.
Stress radiograph
21. Since Ranawat’s classification did not take into consideration the extra-
articular and multiplanar deformities,
Mullaji and Shetty modification:
• Type I—Correctible valgus and an intact MCL.
• Type II—Fixed valgus deformity with an intact MCL.
• Type III—Valgus and hyperextension deformity with an intact MCL.
• Type IV—Valgus and fixed flexion deformity (FFD) with an intact MCL.
• Type V—Severe valgus with a lax MCL.
• Type VI—Valgus secondary to extra-articular deformity.
22. Approaches
• Medial parapatellar approach
• When a medial approach is used in a valgus knee, the surgeon should be very
careful with the MCL detachment: the release of the medial structures should be
minimised in the valgus deformities and limited to overhanging osteophytes.
23. • The main disadvantage of the medial approach is that it is more
difficult to reach the posterolateral corner during the lateral soft
tissue release.
• patellar vascular damage has been described when a medial
parapatellar approach is combined with a lateral release
24. Lateral parapatellar approach
• In 1991, Keblish described for TKA in valgus deformities. He
described a long incision along the lateral border of the quadriceps
muscle, taking care to leave 1 cm of the lateral retinaculum, from the
junction between the vastus lateralis and the quadriceps tendon to
the patella. The patella is dislocated medially.
Keblish PA. The lateral approach to the valgus knee. Surgical
technique and analysis of 53 cases with over two-year
follow-up evaluation. Clin Orthop Relat Res. 1991;271:52–
62.
25. Advantages
• Better visualisation of the tight lateral tissues
• If a lateral retinaculum release is necessary, the patellar vascularisation
will be not compromised.
Disadvantages –
• difficulty in patellar eversion, sometimes requiring TTO,
• less familiarity of many surgeons with this technique
Sekiya H, Takatoku K, Takada H, Sugimoto N, Hoshino Y
(2012) Lateral approach is advantageous in total knee
arthroplasty for valgus deformed knee. Eur J Orthop Surg
Traumatol
26. Bone cuts
Tibia
• The difference between these cases and a standard TKA is the
amount of the resection in grade II and III valgus deformities.
• The resection should be from 6 to 8 mm in the medial
compartment and always has to be performed after having
removed all the osteophytes, especially in the lateral side of the
tibial plateau.
27.
28.
29. Femur
Distal cut:
• femoral cut is reduced valgus degrees of resection from 5–7° to 3° in
order to properly correct pre-operative deformity. Also at this level
lateral condyle distal femoral resection can be minimal (1–2 mm) or
absent in severe valgus deformity of the distal femur.
• Femoral resection should be no more than 10 mm in the medial
condyle (usually 7–8 mm).
30.
31. Anteroposterior cuts:
• The surgeon has to pay attention to lateral condylar hypoplasia that can
lead to internal rotation of the components if a posterior reference is
used.
• In cases of severe trochlear dysplasia, the Whiteside line can be
extremely difficult to identify: in these cases the epicondylar axis or
parallel to the tibial cut technique should be used to assess a correct
femoral rotation.
32.
33.
34. Soft tissue management
Lateral soft tissue
• The best sequence of release of soft tissue structures is still a
controversy among the surgeons
• The releases should be performed using lamina spreaders to check the
tension of the medial and lateral compartments. After each release the
surgeon should evaluate the alignment and the stability of the knee, in
order to achieve a symmetrical rectangular extension and flexion gaps
with the spacer block in situ.
35. • Krackow et al. release the ITB and LCL first in the type I valgus knee, followed by the
POP and the PLC, when necessary.
• Ranawat et al. described a stepwise technique in which the first structure to be
released is the PCL. Then they perform a PLC intra-articular release using an
electrocautery at the level of the tibial cut surface. The ITB is released when necessary
with multiple inside-out stab incisions, as well as the LCL; on the contrary, the POP is
normally preserved.
• Favorito et al. described that more commonly the LCL is the tightest structure, so it is
the first structure to be released. The next release is the POP, followed by the PLC, the
femoral insertion of the LHG and, finally, the ITB can be considered.
36. • A ligament attached to the femur near the epicondyles, so near the
axis through which the tibia rotates and the knee flexes and
extends, has an important role in flexion stability.
• A ligament attached far away from the epicondyle is more
important for the extension knee stability.
Whiteside LA. Selective ligament release in total knee
arthroplasty of the knee in valgus. Clin Orthop Relat
Res. 1999;367:130–140. doi: 10.1097/00003086-
199910000-00016.
37. • the LCL and POP, which are attached to the epicondyle, are
important lateral stabilisers in flexion; these two structures are
appropriate to release for a knee that is tight in flexion. On the
contrary, the ITB and the PLC are important knee stabilisers in
extension, so they should be released when the knee is tighter in
extension
Whiteside LA. Selective ligament release in total knee
arthroplasty of the knee in valgus. Clin Orthop Relat
Res. 1999;367:130–140. doi: 10.1097/00003086-
199910000-00016.
38.
39.
40.
41. Management
Principles.
• Insall described the management of lesser deformities with simple release of the
ITB from its insertion on Gerdy’s tubercle.
• For moderate-to-severe fixed deformities, the lateral femoral condyle would be
stripped of its soft tissue attachments proximally for about 9 cm, and at this level
the periosteum, the iliotibial tract, and the lateral intramuscular septum would
be transversely divided from inside out
42.
43.
44. Because of the risk of posterolateral instability and osteonecrosis following
extensive soft tissue stripping from the lateral femoral condyle, stab-incision
and pie-crusting techniques were developed and have become the methods
of choice. These techniques permit a graduated intra-articular release of the
posterolateral capsule and ITB.
45. • This technique is performed with a moderate amount of stress in the lateral
compartment, using a laminar spreader or ligament tensiometer. Multiple
stab incisions are made in the contracted lateral soft tissues (particularly
the ITB and the portion of the arcuate complex below the popliteus that
tends to tether the popliteus tendon) within and above the joint until the
deformity is corrected.
Pie-crusting method (Insall)
46.
47.
48.
49. FIXED VALGUS DEFORMITY
Sliding lateral epicondylar osteotomy
• in cases with severe fixed valgus deformities or those associated with
flexion contractures. A lateral femoral epicondylar osteotomy
provides correction of the deformity, restoration of the alignment,
and stability of the knee without fixation of the osteotomized bone.
• Scuderi and Insall first described the lateral epicondylar osteotomy in
1995 for noncorrectible fixed valgus deformities >20
50.
51. A ¾ inch osteotome is
placed at the distal leading
edge of the lateral
epicondyle. A shingle of
bone is osteotomized from
the lateral epicondyle that
includes the
popliteus tendon,
lateral collateral ligament,
and posterior capsule.
54. Soft tissue management on medial side
• The medial convex side of the deformity needs to be addressed when medial soft
tissue stretching is significant, with a medial compartment opening in extension of
15 mm or more. Even minimal bone resection creates a medial gap larger than
25 mm,
Possible solutions include
• medial soft tissue re-tensioning
• Medial condyle upslide osteotomy
• use of a varus-valgus constrained (VVC) implant
59. The lateral femoral condyle may have had little or no distal femoral
bone resected or, similarly, little to no bone resected from the chamfer
and posterior cuts, as well. These cuts may require
component augmentation.
60.
61.
62. A lateral release may become necessary
if, after placement of all the implant
components, the patella shows a
tendency to lateral tracking or
subluxation
66. CONCLUSIONS
• Extensive ligamentous releases are often required, but they should be performed
in a progressive manner with recognition of which of the contracted structures is
responsible for extension or flexion gap tensions.
• When extensive ligamentous releases are performed, resection of the PCL and
implantation of a PCL-substituting prosthesis may be advisable to obtain more
reproducible kinematics.
• The deformity should be completely corrected intraoperatively, If residual
ligamentous laxity is present by the end of the procedure,
67. References :
• Insall & Scott SURGERY of the KNEE 6th edition
• Campbell’s Operative Orthopaedics 13th edition
• Sekiya H, Takatoku K, Takada H, Sugimoto N, Hoshino Y (2012)
Lateral approach is advantageous in total knee arthroplasty for
valgus deformed knee. Eur J Orthop
